阅读说明：本技术 发光装置 (Light emitting device ) 是由 福田俊广 于 2019-04-30 设计创作，主要内容包括：本公开的一种实施方式的发光装置,具备多个有机电致发光部和光提取面。通过包括第一电极层侧的第一反射界面、第二电极层侧的第二反射界面、第三反射界面和第四反射界面的构造,形成微腔构造。多个有机电致发光部包括多个第一有机电致发光部和多个第二有机电致发光部,多个第一有机电致发光部在第一波长带发光,多个第二有机电致发光部在波长小于第一波长带的第二波长带发光。微腔构造的第一反射界面和第二反射界面以使第一波长带和第二波长带各自的光增强的方式构成,微腔构造的第三反射界面和第四反射界面以使第一波长带的光减弱且使第二波长带的光增强的方式构成。(The light-emitting device according to one embodiment of the present disclosure includes a plurality of organic electroluminescence light-emitting portions and a light extraction surface. The microcavity structure is formed by a structure including a first reflective interface on the first electrode layer side, a second reflective interface on the second electrode layer side, a third reflective interface, and a fourth reflective interface. The plurality of organic electroluminescence light emitting portions include a plurality of first organic electroluminescence light emitting portions that emit light in a first wavelength band and a plurality of second organic electroluminescence light emitting portions that emit light in a second wavelength band having a wavelength smaller than the first wavelength band. The first and second reflective interfaces of the microcavity structure are configured to enhance the light in the first and second wavelength bands, and the third and fourth reflective interfaces of the microcavity structure are configured to attenuate the light in the first wavelength band and enhance the light in the second wavelength band.)

1. A light-emitting device is provided with:

a plurality of organic electroluminescence light emitting parts each including a first electrode layer, an organic light emitting layer, a second electrode layer having a film thickness of 15nm or more, and a reflective layer in this order; and

A light extraction surface that extracts light emitted from each of the organic electroluminescence light emitting parts through the reflection layer,

the reflective layer comprises 2 reflective interfaces and,

in each of the organic electroluminescent units, a microcavity structure is formed by a structure including a first reflective interface on the organic light emitting layer side of the first electrode layer, a second reflective interface on the organic light emitting layer side of the second electrode layer, and 2 reflective interfaces included in the reflective layer,

The plurality of organic electroluminescence light emitting portions include a plurality of first organic electroluminescence light emitting portions that emit light in a first wavelength band and a plurality of second organic electroluminescence light emitting portions that emit light in a second wavelength band having a wavelength smaller than the first wavelength band,

In each of the first organic electroluminescence light emitting portion and the second organic electroluminescence light emitting portion, the first reflection interface and the second reflection interface of the microcavity structure are configured to enhance light in each of the first wavelength band and the second wavelength band, and the 2 reflection interfaces included in the reflection layer of the microcavity structure are configured to attenuate light in the first wavelength band and enhance light in the second wavelength band.

2. the light emitting device according to claim 1,

The optical distance between the second reflecting interface and 2 reflecting interfaces contained in the reflecting layer is less than or equal to the central wavelength of light emitted from the corresponding organic light-emitting layer.

3. the light-emitting device according to claim 1 or claim 2,

The microcavity structure is a microcavity structure in which a resonance condition is minimum.

4. The light emitting device according to claim 3,

In each of the first organic electroluminescence part and the second organic electroluminescence part, the microcavity structure is configured to satisfy the following expressions (a) to (H).

λa-150＜λa1＜λa+80……(B)

λa-80＜λa2＜λa+80……(D)

λa-150＜λa3＜λa+150……(F)

λa-150＜λa4＜λa+150……(H)

La 1: an optical distance between the first reflective interface and a light-emitting center of the organic light-emitting layer of the first organic electroluminescent section;

La 2: an optical distance between the second reflective interface and a light-emitting center of the organic light-emitting layer of the first organic electroluminescent section;

La 3: an optical distance from an emission center of the organic emission layer of the first organic electroluminescence section to one of 2 reflective interfaces included in the reflective layer;

La 4: an optical distance from an emission center of the organic light emitting layer of the first organic electroluminescence light emitting section to another one of the 2 reflective interfaces included in the reflective layer;

φ a 1: in the first organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when reflected by the first reflective interface changes;

φ a 2: in the first organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when reflected by the second reflection interface changes;

φ a 3: in the first organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when one of the 2 reflection interfaces included in the reflection layer is reflected changes;

φ a 4: in the first organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when the light is reflected by another one of the 2 reflective interfaces included in the reflective layer is changed;

λ a: a center wavelength of an emission spectrum of the organic light emitting layer of the first organic electroluminescence light emitting part;

λ a 1: a wavelength satisfying formula (B);

λ a 2: a wavelength satisfying formula (D);

λ a 3: a wavelength satisfying formula (F);

λ a 4: a wavelength satisfying formula (H);

Ka. And Ja: an integer of 0 or more.

5. The light emitting device according to claim 4,

In each of the first organic electroluminescence part and the second organic electroluminescence part, the microcavity structure is configured to satisfy the following expressions (I) to (P).

λc-150＜λc1＜λc+80……(J)

λc-80＜λc2＜λc+80……(L)

λc-150＜λc3＜λc+150……(N)

λc-150＜λc4＜λc+150……(P)

Lc 1: an optical distance between the first reflective interface and a light-emitting center of the organic light-emitting layer of the second organic electroluminescent section;

lc 2: an optical distance between the second reflective interface and a light-emitting center of the organic light-emitting layer of the second organic electroluminescence light-emitting part;

Lc 3: an optical distance between one of the 2 reflective interfaces included in the reflective layer and an emission center of the organic light-emitting layer of the second organic electroluminescent section;

Lc 4: an optical distance from an emission center of the organic light emitting layer of the second organic electroluminescence section to another one of the 2 reflective interfaces included in the reflective layer;

φ c 1: in the second organic electroluminescent section, a phase of light emitted from the organic light-emitting layer when reflected by the first reflective interface changes;

φ c 2: in the second organic electroluminescent section, a phase of light emitted from the organic light-emitting layer when reflected by the second reflective interface changes;

φ c 3: in the second organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when one of the 2 reflection interfaces included in the reflection layer is reflected is changed;

φ a 4: in the second organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when the light is reflected by another one of the 2 reflective interfaces included in the reflective layer is changed;

λ c: a center wavelength of an emission spectrum of the organic light emitting layer of the second organic electroluminescence light emitting part;

λ c 1: a wavelength satisfying formula (J);

λ c 2: a wavelength satisfying formula (L);

λ c 3: a wavelength satisfying formula (N);

λ c 4: a wavelength satisfying formula (P);

Kc. Jc: an integer of 0 or more.

6. The light-emitting device according to any one of claim 1 to claim 5,

The second electrode layer is formed of a single metal layer having a film thickness of 15nm or more.

7. The light-emitting device according to any one of claim 1 to claim 5,

the second electrode layer includes a first metal layer, a transparent conductor layer, and a second metal layer in this order from the organic light emitting layer side,

The total thickness of the first metal layer and the second metal layer is greater than or equal to 15 nm.

8. the light emitting device according to claim 7,

The first metal layer is thicker than the second metal layer.

9. The light-emitting device according to any one of claim 1 to claim 8,

a circuit board on which a drive circuit for driving each of the organic electroluminescence light emitting parts is formed is further provided on a side opposite to the light extraction surface due to a positional relationship with each of the organic electroluminescence light emitting parts.

10. The light-emitting device according to any one of claims 1 to 9,

The organic light emitting layer is a printed layer.

Technical Field

The present disclosure relates to a light emitting device using an organic Electroluminescence (EL) section that emits light by an EL phenomenon.

Background

In recent years, many proposals have been made on the structure of a light-emitting device using an organic EL element (for example, patent documents 1 to 4).

Disclosure of Invention

In such a light emitting device, it is difficult to secure both power feeding performance and chromaticity viewing angle characteristics with an increase in size of the top emission type. Therefore, it is desirable to provide a light-emitting device which can ensure both power supply performance and viewing angle characteristics of chromaticity.

A light-emitting device according to an embodiment of the present disclosure includes: a plurality of organic electroluminescence light emitting parts each including a first electrode layer, an organic light emitting layer, a second electrode layer having a film thickness of 15nm or more, and a reflective layer in this order; and a light extraction surface for extracting light emitted from each organic electroluminescence light emitting part through the reflection layer. The reflective layer comprises 2 reflective interfaces. In each organic electroluminescence portion, a microcavity structure is formed by a structure including a first reflective interface on the organic light emitting layer side of the first electrode layer, a second reflective interface on the organic light emitting layer side of the second electrode layer, and 2 reflective interfaces included in the reflective layer. The plurality of organic electroluminescence light emitting portions include a plurality of first organic electroluminescence light emitting portions that emit light in a first wavelength band and a plurality of second organic electroluminescence light emitting portions that emit light in a second wavelength band having a wavelength smaller than the first wavelength band. In each of the first organic electroluminescent section and the second organic electroluminescent section, the first reflective interface and the second reflective interface of the microcavity structure are configured to enhance the light in each of the first wavelength band and the second wavelength band, and the 2 reflective interfaces included in the reflective layer of the microcavity structure are configured to attenuate the light in the first wavelength band and enhance the light in the second wavelength band.

according to the light-emitting device of one embodiment of the present disclosure, even when the second electrode layer is a thick film, deterioration of the viewing angle characteristic of chromaticity can be reduced, and therefore, power feeding performance and the viewing angle characteristic of chromaticity can be ensured at the same time. The present invention is not limited to the effects described herein, and any one of the effects described in the present disclosure may be used.

Drawings

Fig. 1 is a cross-sectional view showing a schematic structure of a light-emitting device according to an embodiment of the present disclosure.

Fig. 2 is a cross-sectional view showing the structure of the red light emitting unit shown in fig. 1.

fig. 3 is a cross-sectional view showing the structure of the green light emitting part shown in fig. 1.

fig. 4 is a cross-sectional view showing the structure of the blue light emitting part shown in fig. 1.

fig. 5 is a sectional view for explaining an operation of the light emitting device shown in fig. 1.

Fig. 6 is an example showing a chromaticity change caused by a viewing angle of the light-emitting device of the comparative example.

fig. 7 is an example showing a chromaticity change caused by the viewing angle of the light-emitting device of the comparative example.

Fig. 8 is an example view showing a chromaticity change caused by a viewing angle of the light emitting device shown in fig. 1.

fig. 9 is an example showing a change in the film thickness of the electrode on the light extraction surface side from the 45-degree chromaticity viewing angle of the light-emitting device of the comparative example.

Fig. 10 is an example showing the change in relative luminance of the light-emitting device of the comparative example to the film thickness of the electrode on the light extraction surface side.

fig. 11 is a cross-sectional view showing a modification of the structure of the light emitting section shown in fig. 1.

Fig. 12 is a schematic configuration diagram showing a display device to which the light-emitting device shown in fig. 1 or the like is applied.

fig. 13 is a circuit diagram showing a circuit configuration of the pixel shown in fig. 12.

Fig. 14 is an example of an external appearance of an electronic device to which the display device shown in fig. 12 is applied.

fig. 15 is an example of an external appearance of an illumination device to which the light-emitting device shown in fig. 1 and the like is applied.

Description of the symbols

1 light emitting device

2 display device

3 electronic device

10R Red light emitting part

10G green light emitting part

10B blue light emitting part

11 substrate

12. 12R,12G,12B electrode layer

13R Red organic layer

13G Green organic layer

13B blue organic layer

131R red light emitting layer

131G green light emitting layer

131B blue light-emitting layer

14R,14G,14B electrode layer

15R,15G,15B transparent layer

16R,16G,16B transparent layer

17R,17G,17B transparent layer

18R, 18G, 18B laminate

181R,181G,181B metal layers

182R,182G,182B transparent layer

183R,183G,183B Metal layer

18 pixels

18-1 pixel circuit

18-2 organic electroluminescent part

20 controller

30 driver

31 horizontal selector

32 write scanner

310 casing

320 display surface

410 illumination part

420 ceiling

430 wall

OR, OG, OB luminescence centers

LR red light

LG green light

Light of LB blue

La1, La2, La3, La4, Lb1, Lb2, Lb3, Lb4, Lc1, Lc2, Lc3 and Lc4 optical distances

S1R, S1G, S1B first reflective interface

S2R, S2G, S2B second reflective interface

S3R, S3G, S3B third reflective interface

S4R, S4G, S4B fourth reflective interface

fifth reflective interface S5R, S5G, S5B

Sixth reflective interface S6R, S6G, S6B

SDR, SDG, SDB light extraction surface.

Detailed Description

Embodiments for carrying out the present invention will be described in detail below with reference to the accompanying drawings. The embodiments described below all represent preferred specific examples of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the components of the following embodiments, components that are not recited in the independent claims indicating the uppermost concept of the present invention will be described as arbitrary components. Each drawing is a schematic diagram, and the illustration is not necessarily strict. In the drawings, substantially the same components are denoted by the same reference numerals, and redundant description is omitted or simplified. The following description is made in the order described below.

1. embodiment (light emitting device)

2. Modification (light emitting device)

3. Application example (display device, electronic device, lighting device)

<1 > embodiment >

[ Structure ]

Fig. 1 shows a cross-sectional structure of a main part of a light-emitting device 1 according to an embodiment of the present disclosure. The light-emitting device 1 includes a substrate 11, and a plurality of red light-emitting portions 10R, a plurality of green light-emitting portions 10G, and a plurality of blue light-emitting portions 10B are provided on the substrate 11. The red light emitting portion 10R corresponds to a specific example of the "organic electroluminescence light emitting portion" or the "first organic electroluminescence light emitting portion" of the present disclosure. The green light emitting section 10G corresponds to a specific example of the "organic electroluminescence section" and the "first organic electroluminescence section" of the present disclosure. The blue light emitting section 10B corresponds to a specific example of the "organic electroluminescence section" and the "second organic electroluminescence section" of the present disclosure.

The red light emitting section 10R includes an electrode layer 12R, a red organic layer 13R including a red light emitting layer 131R, an electrode layer 14R, a transparent layer 15R, a transparent layer 16R, and a transparent layer 17R in this order on the substrate 11. The green light emitting section 10G has an electrode layer 12G, a green organic layer 13G including a green light emitting layer 131G, an electrode layer 14G, a transparent layer 15G, a transparent layer 16G, and a transparent layer 17G in this order on the substrate 11. The blue light emitting section 10B includes an electrode layer 12B, a blue organic layer 13B including a blue light emitting layer 131B, an electrode layer 14B, a transparent layer 15B, a transparent layer 16B, and a transparent layer 17B in this order on a substrate 11. The electrode layers 12R,12G, and 12B correspond to a specific example of "the first electrode layer" in the present disclosure. The electrode layers 14R,14G, and 14B correspond to a specific example of "second electrode layer" in the present disclosure. The laminate composed of the transparent layer 15R, the transparent layer 16R, and the transparent layer 17R corresponds to a specific example of the "reflective layer" of the present disclosure. The laminate composed of the transparent layer 15G, the transparent layer 16G, and the transparent layer 17G corresponds to a specific example of the "reflective layer" of the present disclosure. The laminate composed of the transparent layer 15B, the transparent layer 16B, and the transparent layer 17B corresponds to a specific example of the "reflective layer" of the present disclosure.

The red light emitting portion 10R emits light (red light LR) in a red wavelength range from the transparent layer 17R side, and the red light LR is generated in the red light emitting layer 131R by injecting current from the electrode layer 12R and the electrode layer 14R. The green light emitting portion 10G emits light in the green wavelength range (green light LG) from the transparent layer 17G side, and the green light LG is generated in the green light emitting layer 131G by injecting current through the electrode layers 12G and 14G. The blue light emitting section 10B emits light (blue light LB) in the blue wavelength range from the transparent layer 17B side, and the blue light LB is generated in the blue light emitting layer 131B by injecting current from the electrode layer 12B and the electrode layer 14B. The light emitting device 1 is configured to: the light emitted from the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B is multiply reflected between the electrode layers 12R,12G, and 12B and the transparent layers 17R,17G, and 17B, respectively, and the light is extracted from the transparent layers 17R,17G, and 17B. That is, the light emitting device 1 is a top emission type light emitting device having a resonator structure.

the substrate 11 is a plate-like member for supporting the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B, and is formed of, for example, a transparent glass substrate, a semiconductor substrate, or the like. The substrate 11 may be formed of an elastic substrate (flexible substrate). The substrate 11 may be a circuit substrate provided with a circuit (pixel circuit 18-1 described later) for driving the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B.

The electrode layers 12R,12G, and 12B are anode electrodes and function as mirrors. The electrode layers 12R,12G, and 12B are formed of, for example, a light reflective material. As the light reflective material for the electrode layers 12R,12G,12B, there can be mentioned: for example, aluminum (Al), aluminum alloy, platinum (Pt), gold (Au), chromium (Cr), tungsten (W), or the like. The electrode layers 12R,12G, and 12B may be formed by laminating a transparent conductive material and a light reflective material, for example. The thickness of the electrode layers 12R,12G,12B is, for example, 100nm to 300 nm.

The red organic layer 13R has, for example, in order from a position close to the electrode layer 12R: a hole injection layer, a hole transport layer, a red light emitting layer 131R, an electron transport layer, and an electron injection layer. The green organic layer 13G has, for example, in order from a position close to the electrode layer 12G: a hole injection layer, a hole transport layer, a green light emitting layer 131G, an electron transport layer, and an electron injection layer. The blue organic layer 13B has, for example, in order from a position close to the electrode layer 12B: a hole injection layer, a hole transport layer, a blue light emitting layer 131B, an electron transport layer, and an electron injection layer.

the hole injection layer is a layer for preventing leakage. The hole injection layer is formed of, for example, Hexaazatriphenylene (HAT) or the like. The thickness of the hole injection layer is, for example, 1nm to 20 nm. The hole transport layer is formed of, for example,. alpha. -NPD [ N, N '-di (1-naphthyl) -N, N' -diphenylyl- [ 1,1 '-biphenyl ] -4, 4' -diamine ]. The thickness of the hole transport layer is, for example, 15nm to 100 nm.

The red, green, and blue light emitting layers 131R, 131G, and 131B are configured to emit light of a predetermined color by combination of holes and electrons. The thicknesses of the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B are, for example, 5nm to 50 nm. The red light-emitting layer 131R emits light in a red wavelength range (first wavelength band). The red light-emitting layer 131R is formed of, for example, rubrene doped with a Pyrromethene (Pyrromethene) boron complex. In this case, rubrene is used as a host material. The green light-emitting layer 131G emits light in a green wavelength range (first wavelength band). The green light-emitting layer 131G is formed of, for example, Alq3 (trihydroxyquinoline (Trisquinolinol) aluminum complex). The blue light-emitting layer 131B emits light of a blue wavelength range (a second wavelength band having a wavelength shorter than the first wavelength band) having a wavelength shorter than the red wavelength range. The blue light-emitting layer 131B is formed of, for example, ADN (9, 10-di (2-naphthyl) anthracene) doped with a Diamino chrysene (Diamino chrysene) derivative. In this case, ADN is used as a host material, and is, for example, a vapor-deposited film having a thickness of 20 nm. The diaminochrysin derivative is used as a dopant material, and is doped, for example, at a film thickness ratio of 5%.

the electron transport layer is formed of BCP (2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline). The thickness of the electron transport layer is, for example, 15nm to 200 nm. The electron injection layer is formed of, for example, lithium fluoride (LiF). The thickness of the electron injection layer is, for example, 15nm to 270 nm.

The electrode layers 14R,14G, and 14B are cathode electrodes and function as mirrors. The electrode layers 14R,14G,14B are formed of a metal material having a high reflectance. The electrode layers 14R,14G, and 14B are formed of, for example, magnesium (Mg), silver (Ag), or an alloy thereof. The electrode layers 14R,14G, and 14B are each formed of a single metal layer having a thickness of, for example, 15nm to 55 nm. When the electrode layers 14R,14G, and 14B are formed of such a metal material having a high reflectance, the effect of the resonator structure can be improved, and the light extraction efficiency can be improved. This also makes it possible to suppress power consumption and to extend the life of the red light emitting section 10R, the green light emitting section 10G, and the blue light emitting section 10B. Further, with reference to the light extraction efficiency when the thickness of electrode layers 14R,14G, and 14B is 15nm and the resistance value of electrode layers 14R,14G, and 14B, the product of the current ratio (reciprocal of the relative efficiency) and the resistance ratio is 1 or more, and the upper limit value of the thickness of electrode layers 14R,14G, and 14B is 55 nm.

The transparent layers 15R,15G,15B, the transparent layers 16R,16G,16B, and the transparent layers 17R,17G,17B are disposed on the light extraction side of the light-emitting device 1. The thickness of the transparent layers 15R,15G,15B is, for example, 30nm to 450nm, the thickness of the transparent layers 16R,16G,16B is, for example, 30nm to 380nm, and the thickness of the transparent layers 17R,17G,17B is, for example, 500nm to 10000 nm.

The transparent layers 15R,15G,15B, the transparent layers 16R,16G,16B, and the transparent layers 17R,17G,17B are formed of, for example, a transparent conductive material or a transparent dielectric material. As the transparent conductive material used for the transparent layers 15R,15G,15B, 16R,16G,16B, 17R,17G,17B, ito (indium Tin oxide), Indium Zinc Oxide (IZO), or the like can be cited, for example. Examples of the transparent dielectric material used for the transparent layers 15R,15G,15B, the transparent layers 16R,16G,16B, and the transparent layers 17R,17G,17B include silicon oxide (SiO2), silicon oxynitride (SiON), silicon nitride (SiN), or the like. The transparent layers 15R,15G, and 15B, the transparent layers 16R,16G, and 16B, and the transparent layers 17R,17G, and 17B may be configured to function as a cathode electrode or a passivation film. Low refractive index materials such as MgF or NaF may be used for the transparent layers 15R,15G,15B, the transparent layers 16R,16G,16B, and the transparent layers 17R,17G, 17B.

The transparent layers 17R,17G, and 17B may be provided with a film thickness of 1 μm or more. The layer is formed of, for example, a transparent conductive material, a transparent insulating material, a resin material, glass, or the like. The layer may also be constituted by an air layer. By providing such a layer, interference from the outside with the resonator structure formed between the electrode layers 12R,12G, and 12B and the transparent layers 17R,17G, and 17B can be prevented.

Next, the resonator structure of red light emitting unit 10R, green light emitting unit 10G, and blue light emitting unit 10B will be described. Fig. 2 is a sectional view showing the structure of the red light emitting unit 10R. Fig. 3 is a cross-sectional view showing the structure of the green light emitting section 10G. Fig. 4 is a cross-sectional view showing the structure of the blue light emitting section 10B.

The red light emitting unit 10R includes, in order from the substrate 11 side: a first reflective interface S1R, a second reflective interface S2R, a third reflective interface S3R, a fourth reflective interface S4R, and a light extraction plane SDR. The third reflective interface S3R and the fourth reflective interface S4R are included in the stacked body constituted by the transparent layer 15R, the transparent layer 16R, and the transparent layer 17R. At this time, a microcavity structure is formed by a structure including the first reflective interface S1R, the second reflective interface S2R, the third reflective interface S3R, and the fourth reflective interface S4R. The microcavity configuration has, for example, the following effects: light of a specific wavelength (for example, light in a red wavelength range) is enhanced by resonance of light generated between the electrode layer 12R and the electrode layer 14R. Between the first reflective interface S1R and the second reflective interface S2R, the emission center OR of the red light-emitting layer 131R is provided. In other words, the red light-emitting layer 131R is provided between the first reflective interface S1R and the light extraction surface SDR which face each other. The first reflective interface S1R is the interface between the electrode layer 12R and the red organic layer 13R. The second reflective interface S2R is the interface between the red organic layer 13R and the electrode layer 14R. The third reflective interface S3R is an interface of the transparent layer 15R and the transparent layer 16R. The fourth reflective interface S4R is an interface of the transparent layer 16R and the transparent layer 17R. The light extraction surface SDR is the outermost surface of the red light-emitting part 10R. The outermost surface of the red light-emitting portion 10R is in contact with, for example, an air layer. The light emitted from the red light emitting portion 10R is extracted from the light extraction surface SDR through the transparent layers 15R, 16R, 17R.

The green light emitting section 10G includes, in order from the substrate 11 side: a first reflective interface S1G, a second reflective interface S2G, a third reflective interface S3G, a fourth reflective interface S4G, and a light extraction surface SDG. The third reflective interface S3G and the fourth reflective interface S4G are included in a stacked body composed of the transparent layer 15G, the transparent layer 16G, and the transparent layer 17G. At this time, a microcavity structure is formed by a structure including the first reflective interface S1G, the second reflective interface S2G, the third reflective interface S3G, and the fourth reflective interface S4G. The microcavity configuration has, for example, the following effects: light of a specific wavelength (for example, light in a green wavelength range) is enhanced by resonance of light generated between the electrode layer 12G and the electrode layer 14G. Between the first reflective interface S1G and the second reflective interface S2G, a light emission center OG of the green light-emitting layer 131G is provided. In other words, the green light-emitting layer 131G is provided between the first reflective interface S1G and the light extraction surface SDG, which face each other. The first reflective interface S1G is the interface between the electrode layer 12G and the green organic layer 13G. The second reflective interface S2G is the interface between the green organic layer 13G and the electrode layer 14G. The third reflective interface S3G is an interface of the transparent layer 15G and the transparent layer 16G. The fourth reflective interface S4G is an interface of the transparent layer 16G and the transparent layer 17G. The light extraction surface SDG is the outermost surface of the green light emitting section 10G. The outermost surface of the green light-emitting part 10G is in contact with, for example, an air layer. The light emitted from the green light emitting section 10G is extracted from the light extraction surface SDG through the transparent layers 15G, 16G, and 17G.

The blue light emitting section 10B includes, in order from the substrate 11 side: a first reflective interface S1B, a second reflective interface S2B, a third reflective interface S3B, a fourth reflective interface S4B, and a light extraction surface SDB. The third reflective interface S3B and the fourth reflective interface S4B are included in the stacked body constituted by the transparent layer 15B, the transparent layer 16B, and the transparent layer 17B. At this time, a microcavity structure is formed by a structure including the first reflective interface S1B, the second reflective interface S2B, the third reflective interface S3B, and the fourth reflective interface S4B. The microcavity configuration has, for example, the following effects: light of a specific wavelength (for example, light in the blue wavelength range) is enhanced by resonance of light generated between the electrode layer 12B and the electrode layer 14B. Between the first reflective interface S1B and the second reflective interface S2B, the light emission center OB of the blue light-emitting layer 131B is provided. In other words, the blue light-emitting layer 131B is provided between the first reflective interface S1B and the light extraction surface SDB, which face each other. The first reflective interface S1B is the interface between the electrode layer 12B and the blue organic layer 13B. The second reflective interface S2B is the interface between the blue organic layer 13B and the electrode layer 14B. The third reflective interface S3B is an interface of the transparent layer 15B and the transparent layer 16B. The fourth reflective interface S4B is the interface of the transparent layer 16B and the transparent layer 17B. The light extraction surface SDB is the outermost surface of the blue light emitting portion 10B. The outermost surface of the blue light-emitting portion 10B is in contact with, for example, an air layer. The light emitted from the blue light emitting portion 10B is extracted from the light extraction surface SDB through the transparent layers 15B, 16B, 17B.

the first reflective interfaces S1R, S1G, S1B and the second reflective interfaces S2R, S2G, S2B are made of a reflective film of metal. The third reflective interfaces S3R, S3G, S3B and the fourth reflective interfaces S4R, S4G, S4B are constituted by interfaces having a refractive index difference of 0.15 or more, for example.

(first reflective interface S1R, S1G, S1B)

The electrode layers 12R,12G, and 12B are formed of aluminum (Al) having a refractive index of 0.73 and an extinction coefficient of 5.91, and the red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B are formed of a material having a refractive index of 1.75. In this case, the first reflective interface S1R is disposed at an optical distance La1 from the light emission center OR, the first reflective interface S1G is disposed at an optical distance Lb1 from the light emission center OG, and the first reflective interface S1B is disposed at an optical distance Lc1 from the light emission center OB.

The optical distance La1 is set to: the light of the center wavelength λ a of the emission spectrum of the red light-emitting layer 131R (the light of the red wavelength range (first wavelength band)) is mutually intensified by the interference between the first reflective interface S1R and the emission center OR. The optical distance Lb1 is set to: the light of the center wavelength λ b of the emission spectrum of the green light-emitting layer 131G (light in the green wavelength range (first wavelength band)) is mutually intensified by the interference between the first reflective interface S1G and the light emission center OG. The optical distance Lc1 is set to: the light of the center wavelength λ c of the emission spectrum of the blue light-emitting layer 131B (light of the blue wavelength range (second wavelength band)) is mutually intensified by the interference between the first reflective interface S1B and the light emission center OB.

Specifically, the optical distances La1, Lb1, Lc1 satisfy the following expressions (1) to (6).

λa-150＜λa1＜λa+80……(2)

λb-150＜λb1＜λb+80……(4)

λc-150＜λc1＜λc+80……(6)

Wherein, Na, Nb, Nc: an integer of 0 or more

Units of λ a, λ a1, λ b1, λ c 1: nm (length)

φ a 1: the phase change of the light emitted from the red light-emitting layer 131R when reflected by the first reflective interface S1R

φ b 1: the phase change of the light emitted from the green light-emitting layer 131G when reflected by the first reflective interface S1G

φ c 1: the phase change of the light emitted from the blue light-emitting layer 131B when reflected by the first reflective interface S1B

λ a 1: a wavelength satisfying the formula (2)

λ b 1: a wavelength satisfying the formula (4)

λ c 1: a wavelength satisfying the formula (6)

Φ a1 can be calculated using N0 and k of the complex refractive index N ═ N0-jk (N0: refractive index, k: extinction coefficient) of the constituent materials of the electrode layers 12R,12G,12B, and the refractive indices of the red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B (see Principles of Optics, Max Born and Emil Wolf, 1974(pergam PRESS), for example). The refractive index of each constituent material can be measured using a Spectroscopic (Spectroscopic) measurement apparatus.

If the values of Na, Nb, and Nc are large, a so-called microcavity (micro resonator) effect may not be obtained. For this reason, Na ═ 0, Nb ═ 0, and Nc ═ 0 are preferable. When the optical distance La1 satisfies the above equations (1) and (2), λ a1 can be greatly shifted from the center wavelength λ a. Similarly, when the optical distance Lb1 satisfies the above equations (3) and (4), λ b1 can be greatly shifted from the center wavelength λ b. When the optical distance Lc1 satisfies the above equations (5) and (6), λ c1 can be greatly shifted from the center wavelength λ c.

(second reflective interface S2R, S2G, S2B)

the red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B are formed of a material having a refractive index of 1.75, and the electrode layers 14R,14G, and 14B are formed of silver (Ag) having a refractive index of 0.13 and an extinction coefficient of 3.96. In this case, the second reflective interface S2R is disposed at an optical distance La2 from the light emission center OR, the second reflective interface S2G is disposed at an optical distance Lb2 from the light emission center OG, and the second reflective interface S2B is disposed at an optical distance Lc2 from the light emission center OB.

The optical distance La2 is set to: the light of the center wavelength λ a of the emission spectrum of the red light-emitting layer 131R (the light of the red wavelength range (first wavelength band)) is mutually intensified by the interference between the second reflective interface S2R and the emission center OR. The optical distance Lb2 is set to: the light of the center wavelength λ b of the emission spectrum of the green light-emitting layer 131G (light of the green wavelength range (first wavelength band)) is mutually intensified by the interference between the second reflective interface S2G and the light emission center OG. The optical distance Lc2 is set to: the light of the center wavelength λ c of the emission spectrum of the blue light-emitting layer 131B (light of the blue wavelength range (second wavelength band)) is mutually intensified by the interference between the second reflective interface S2B and the light emission center OB.

Specifically, the optical distances La2, Lb2, Lc2 satisfy the following expressions (7) to (12).

λa-80＜λa2＜λa+80……(8)

λb-80＜λb2＜λb+80……(10)

λc-80＜λc2＜λc+80……(12)

Wherein, Ma, Mb, Mc: an integer of 0 or more

Units of λ a, λ a2, λ b2, λ c 2: nm (length)

φ a 2: the phase change of the light emitted from the red light-emitting layer 131R when reflected by the second reflective interface S2R

φ b 2: the phase change of the light emitted from the green light-emitting layer 131G when reflected by the second reflective interface S2G

φ c 2: the phase change of the light emitted from the blue light-emitting layer 131B when reflected by the second reflective interface S2B

λ a 2: a wavelength satisfying the formula (8)

λ b 2: a wavelength satisfying the formula (10)

λ c 2: a wavelength satisfying the formula (12)

φ a2 can be obtained by the same method. If the values of Ma, Mb, Mc are large, the so-called microcavity (microresonator) effect may not be obtained. For this reason, Ma is preferably 0, Mb is 0, and Mc is 0.

Here, Na is 0, Nb is 0, Nc is 0, Ma is 0, Mb is 0, and Mc is 0. In this case, a microcavity structure having the smallest resonance condition is formed by the structure including the first reflective interface S1R, the second reflective interface S2R, the third reflective interface S3R, and the fourth reflective interface S4R. In this case, the first reflective interface S1R and the second reflective interface S2R of the microcavity structure having the smallest resonance condition in the red light-emitting member 10R are configured to increase the light in the red wavelength range, and the third reflective interface S3R and the fourth reflective interface S4R are configured to decrease the light in the red wavelength range. Similarly, a microcavity structure having the smallest resonance condition is formed by a structure including the first reflective interface S1G, the second reflective interface S2G, the third reflective interface S3G, and the fourth reflective interface S4G. In this case, the first reflective interface S1G and the second reflective interface S2G of the microcavity structure that minimizes the resonance condition of the green light-emitting part 10G are configured to enhance the light in the green wavelength range, and the third reflective interface S3G and the fourth reflective interface S4G are configured to attenuate the light in the green wavelength range. Further, a microcavity structure having the smallest resonance condition is formed by the structure including the first reflective interface S1B, the second reflective interface S2B, the third reflective interface S3B, and the fourth reflective interface S4B. In this case, the first reflective interface S1B and the second reflective interface S2B of the microcavity structure that minimizes the resonance condition of the blue light-emitting part 10B are configured to enhance light in the blue wavelength range, and the third reflective interface S3B and the fourth reflective interface S4B are configured to enhance light in the blue wavelength range.

When the optical distance La1 satisfies the above equations (1) and (2) and the optical distance La2 satisfies the above equations (7) and (8), a peak of transmittance occurs at a predetermined wavelength due to the amplification effect of the first reflective interface S1R and the second reflective interface S2R. When the optical distance Lb1 satisfies the above equations (3) and (4) and the optical distance Lb2 satisfies the above equations (9) and (10), a peak of transmittance occurs at a predetermined wavelength due to the amplification effect of the first reflective interface S1G and the second reflective interface S2G. When the optical distance Lc1 satisfies the above equations (5) and (6) and the optical distance Lc2 satisfies the above equations (11) and (12), a peak of transmittance occurs at a predetermined wavelength due to the amplification effect of the first reflective interface S1B and the second reflective interface S2B.

(third reflective interface S3R, S3G, S3B)

The optical distance La3 is set to, for example: the light of the center wavelength λ a of the emission spectrum of the red light-emitting layer 131R is attenuated from each other by the interference between the third reflective interface S3R and the emission center OR. At this time, the optical distance between the second reflective interface S2R and the third reflective interface S3R is equal to or less than the center wavelength λ a of the light emitted from the red light-emitting layer 131R. The optical distance Lb3 is set to, for example: the light of the center wavelength λ b of the emission spectrum of the green light-emitting layer 131G is attenuated by the interference between the third reflective interface S3G and the light emission center OG. At this time, the optical distance between the second reflective interface S2G and the third reflective interface S3G is equal to or less than the center wavelength λ b of the light emitted from the green light-emitting layer 131G. The optical distance Lc3 is set to, for example: by the interference between the third reflective interface S3B and the light emission center OB, the light of the center wavelength λ c of the emission spectrum of the blue light-emitting layer 131B is mutually intensified. At this time, the optical distance between the second reflective interface S2B and the third reflective interface S3B is equal to or less than the center wavelength λ c of the light emitted from the blue light-emitting layer 131B.

the optical distances La3, Lb3, and Lc3 satisfy the following expressions (13) to (18), for example.

λa-150＜λa3＜λa+150……(14)

λb-150＜λb3＜λb+150……(16)

λc-150＜λc3＜λc+150……(18)

Wherein, Ka, Kb, Kc: an integer of 0 or more

Units of λ a, λ a3, λ b3, λ c 3: nm (length)

φ a 3: the phase change of the light emitted from the red light-emitting layer 131R when reflected by the third reflective interface S3R

φ b 3: the phase change of the light emitted from the green light-emitting layer 131G when reflected by the third reflective interface S3G

φ c 3: the phase change of the light emitted from the blue light-emitting layer 131B when reflected by the third reflective interface S3B

λ a 3: a wavelength satisfying the formula (14)

λ b 3: a wavelength satisfying the formula (16)

λ c 3: a wavelength satisfying the formula (18)

φ a3 can be obtained by the same method. When the optical distances La3, Lb3, and Lc3 satisfy the above-described equations (13) to (18), the light emission state of each light-emitting portion (red light-emitting portion 10R, green light-emitting portion 10G, and blue light-emitting portion 10B) can be adjusted. By adding the reflection at the third reflective interface S3R in this manner, the light generated in the red light-emitting layer 131R can be reduced, and the full width at half maximum of the spectrum can be widened. By adding the reflection at the third reflective interface S3G, the light generated in the green light-emitting layer 131G can be reduced, and the full width at half maximum of the spectrum can be broadened. By adding the reflection at the third reflective interface S3B, the light generated in the blue light-emitting layer 131B can be enhanced, and the full width at half maximum of the spectrum can be narrowed.

(fourth reflective interface S4R, S4G, S4B)

The optical distance La4 is set to, for example: the light of the center wavelength λ a of the emission spectrum of the red light-emitting layer 131R is attenuated from each other by the interference between the fourth reflective interface S4R and the emission center OR. At this time, the optical distance between the second reflective interface S2R and the fourth reflective interface S4R is equal to or less than the center wavelength λ a of the light emitted from the red light-emitting layer 131R. The optical distance Lb4 is set to, for example: the light of the center wavelength λ b of the emission spectrum of the green light-emitting layer 131G is attenuated by the interference between the fourth reflective interface S4G and the light emission center OG. At this time, the optical distance between the second reflective interface S2G and the fourth reflective interface S4G is equal to or less than the center wavelength λ b of the light emitted from the green light-emitting layer 131G. The optical distance Lc4 is set to, for example: by the interference between the fourth reflective interface S4B and the light emission center OB, the light of the center wavelength λ c of the emission spectrum of the blue light-emitting layer 131B is mutually intensified. At this time, the optical distance between the second reflective interface S2B and the fourth reflective interface S4B is equal to or less than the center wavelength λ c of the light emitted from the blue light-emitting layer 131B.

The optical distances La4, Lb4, and Lc4 satisfy the following expressions (19) to (24), for example.

λa-150＜λa4＜λa+150……(20)

λb-150＜λb4＜λb+150……(22)

λc-150＜λc4＜λc+150……(24)

Wherein Ja, Jb, Jc: an integer of 0 or more

Units of λ a, λ a4, λ b4, λ c 4: nm (length)

φ a 4: the phase change of the light emitted from the red light-emitting layer 131R when reflected by the fourth reflective interface S4R

φ b 4: the phase change of the light emitted from the green light-emitting layer 131G when reflected by the fourth reflective interface S4G

φ c 4: the phase change of the light emitted from the blue light-emitting layer 131B when reflected by the fourth reflective interface S4B

λ a 4: a wavelength satisfying the formula (20)

λ b 4: a wavelength satisfying the formula (22)

λ c 4: a wavelength satisfying the formula (24)

φ a4 can be obtained by the same method. When the optical distances La3, Lb3, and Lc3 satisfy the above-described equations (13) to (18), and the optical distances La4, Lb4, and Lc4 satisfy the above-described equations (19) to (24), the light emission state of each of the light-emitting parts (the red light-emitting part 10R, the green light-emitting part 10G, and the blue light-emitting part 10B) can be adjusted. By adding the reflection at the fourth reflective interfaces S4R, S4G, and S4B in this manner, the peak profiles of the spectra of the light generated in the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B can be adjusted to a desired profile. As a result, for example, abrupt changes in luminance and chromaticity due to an angle can be suppressed. In addition, for example, by making the spectrum of light generated in the light-emitting layer have a sharp peak, the light extraction efficiency can be improved. In addition, the chromaticity point can be increased.

The light-emitting device 1 can be manufactured by sequentially forming the electrode layers 12R,12G, and 12B, the organic layers (the red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B), the electrode layers 14R,14G, and 14B, the transparent layers 15R,15G, and 15B, the transparent layers 16R,16G, and 16B, and the transparent layers 17R,17G, and 17B on the substrate 11. The red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B may be formed by vapor deposition or printing. In other words, the red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B may be printed layers. The electrode layers 14R,14G, and 14B may be formed of a common layer. In this case, the material and thickness of the electrode layers 14R,14G,14B are the same. The transparent layers 15R,15G, and 15B may be formed of a common layer. In this case, the material and thickness of the transparent layers 15R,15G,15B are the same. The transparent layers 16R,16G, and 16B may be formed of layers common to each other. In this case, the material and thickness of the transparent layers 16R,16G,16B are the same. The transparent layers 17R,17G, and 17B may be formed of layers common to each other. In this case, the material and thickness of the transparent layers 17R,17G,17B are the same.

[ Effect, Effect ]

In the light-emitting device 1 described above, the drive current is injected into the light-emitting layers (the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B) of the red light-emitting portion 10R, the green light-emitting portion 10G, and the blue light-emitting portion 10B through the electrode layers 12R,12G, and 12B and the electrode layers 14R,14G, and 14B. The result is: in each light-emitting layer, the holes and the electrons recombine to generate excitons, thereby emitting light.

as shown in fig. 5, the light generated in the red organic layer 13R is multiply reflected between the first reflective interface S1R and the fourth reflective interface S4R, and is extracted from the light extraction surface SDR. In red light emitting unit 10R, red light LR is extracted from light extraction surface SDR; in the green light emitting part 10G, green light LG is extracted from the light extraction surface SDG; in the blue light emitting section 10B, the blue light LB is extracted from the light extraction surface SDB. By additive color mixing of the red light LR, the green light LG, and the blue light LB, various colors can be displayed.

However, in the light emitting device having such a resonator structure, various structures have been proposed, but it is not easy to improve the light distribution characteristics.

for example, it is proposed that: a method of setting a film thickness between the light-transmissive electrode and the reflective electrode so that light of a desired wavelength resonates, thereby improving light emission efficiency (see, for example, patent document 1). In addition, attempts have also been made to: by controlling the film thickness of the organic layer, the balance of the attenuations of the 3 primary colors (red, green, and blue) is controlled, and the viewing angle characteristics of the white chromaticity point are improved (see, for example, patent document 4).

however, such a resonator structure functions as a narrow interference filter having a full width at half maximum for extracting a spectrum of light; therefore, when the light extraction surface is viewed obliquely, the wavelength of light is greatly shifted. Therefore, the viewing angle dependence becomes large due to, for example, a decrease in emission intensity from the viewing angle.

In addition, patent document 2 proposes a structure for reducing chromaticity variation due to the viewing angle. However, this structure is applicable to a single color, and reduces the viewing angle dependence of luminance, but is not easily applicable to a sufficiently wide wavelength band. Although in order to extend the applicable wavelength band, it is conceivable to increase the reflectance; in this case, however, the light extraction efficiency is significantly reduced.

as described above, although a method of reducing the angle dependence by adjusting the positional relationship, the light emission position, and the like within the resonator structure may be considered; however, this method may not be easily adjusted. For example, wavelength dispersion of refractive index occurs due to the spectrum of light emitted from each light-emitting layer. In the wavelength dispersion of the refractive index, the refractive index of the constituent material differs for each wavelength, and therefore the effect of the resonator structure differs among the red organic EL element, the green organic EL element, and the blue organic EL element. For example, in a red organic EL element, the peak value of the extracted red light becomes too steep; in the blue organic EL element, the peak of the extracted blue light becomes too gentle. As such, if at each element region, the effect of the resonator configuration is greatly different; the angular dependence of luminance and chromaticity becomes large, and the light distribution characteristics are degraded.

In contrast, in the light-emitting device 1 of the present embodiment, the third reflective interface S3R and the fourth reflective interface S4R have different influences on the light generated in the red light-emitting layer 131R from the third reflective interface S3B and the fourth reflective interface S4B on the light generated in the blue light-emitting layer 131B. Similarly, in the light-emitting device 1 of the present embodiment, the influence of the third reflective interface S3G and the fourth reflective interface S4G on the light generated in the green light-emitting layer 131G is different from the influence of the third reflective interface S3B and the fourth reflective interface S4B on the light generated in the blue light-emitting layer 131B. For example, light generated in the red, green, and blue light emitting layers 131R, 131G, and 131B is as follows.

the light generated in the red light-emitting layer 131R is attenuated by the interference between the emission center OR of the red light-emitting layer 131R and the third and fourth reflective interfaces S3R and S4R. Similarly, the light generated in the green light-emitting layer 131G is attenuated by the interference between the light emission center OG of the green light-emitting layer 131G and the third and fourth reflective interfaces S3G and S4G. On the other hand, the light generated in the blue light-emitting layer 131B is enhanced by the interference between the light emission center OB of the blue light-emitting layer 131B and the third and fourth reflective interfaces S3B and S4B.

Thus, red light LR having a gentle peak value can be extracted from light extraction surface SDR in red light emitting unit 10R; the green light emitting unit 10G can extract green light LG having a gradual peak from the light extraction surface SDG; in the blue light emitting section 10B, the blue light LB having a sharp peak can be extracted from the light extraction surface SDB. Therefore, the difference between the effect of the resonator structure of red light emitting unit 10R and green light emitting unit 10G and the effect of the resonator structure of blue light emitting unit 10B is small, and the angular dependence of luminance and chromaticity is small. Therefore, the light distribution characteristics can be improved. In addition, the light-emitting device 1 having high light distribution characteristics is also suitable for a display device requiring high image quality, and the productivity of the display device can be improved.

Fig. 6 shows an example of chromaticity change due to the viewing angle of the light-emitting device of the comparative example. In the light-emitting device of the comparative example, the electrode layer on the substrate side was made of a single layer of Al alloy, and the electrode layer on the light extraction surface side was made of a single layer of Ag alloy. In the light-emitting device of the comparative example, the resonance condition between the electrode layer on the substrate side and the light-emission center is 0 (that is, Na, Nb, and Nc are 0), the resonance condition between the electrode layer on the light extraction surface side and the light-emission center is 1 (that is, Ma, Mb, and Mc are 1), and the third reflective interfaces S3R, S3G, S3B, and the fourth reflective interfaces S4R, S4G, and S4B are not formed. At this time, in the light emitting device of the comparative example, the second cavity structure was formed by the structure including the first reflective interfaces S1R, S1G, S1B and the second reflective interfaces S2R, S2G, S2B. In the light-emitting device of the comparative example, the third reflective interfaces S3R, S3G, and S3B and the fourth reflective interfaces S4R, S4G, and S4B of the present embodiment are not provided. Fig. 6 shows the results of the light-emitting device according to the comparative example, in which the film thickness t of the electrode layer on the light extraction surface side was 13nm or 21 nm.

Fig. 7 shows an example of chromaticity change due to the viewing angle of the light-emitting device of the comparative example. Fig. 7 shows the results when the thickness t of the electrode layer on the light extraction surface side was 21nm, Na, Nb, and Nc were 0, and Ma, Mb, and Mc were 1 and 0.

Fig. 8 shows an example of chromaticity change due to the viewing angle of the light-emitting device 1 of the embodiment. In the light-emitting device 1 of the embodiment, the electrode layers 12R,12G, and 12B are made of a single layer of Al alloy, and the electrode layers 14R,14G, and 14B are made of a single layer of Ag alloy with a film thickness of 18 nm. In the light-emitting device 1 of the embodiment, the results are shown when Na, Nb, and Nc are 0, and Ma, Mb, and Mc are 1 and 0. Further, in the light emitting device of the embodiment, the third reflective interfaces S3R, S3G, S3B and the fourth reflective interfaces S4R, S4G, S4B are provided. Further, in the light emitting device 1 of the embodiment, the optical distance La3 is set to: the light of the center wavelength λ a of the emission spectrum of the red light-emitting layer 131R is attenuated from each other by the interference between the third reflective interface S3R and the emission center OR. The optical distance Lb3 is set to: the light of the center wavelength λ b of the emission spectrum of the green light-emitting layer 131G is attenuated by the interference between the third reflective interface S3G and the light emission center OG. The optical distance Lc3 is set to: by the interference between the third reflective interface S3B and the light emission center OB, the light of the center wavelength λ c of the emission spectrum of the blue light-emitting layer 131B is mutually intensified.

as is clear from fig. 6, when the film thickness t of the electrode layer on the light extraction surface side is 13nm, the chromaticity exceeds 0.020 from the vicinity of the viewing angle exceeding 50 degrees, and 0.020 is 1 index of the viewing angle dependence. Further, as is clear from fig. 6, if the film thickness t of the electrode layer on the light extraction surface side is increased from 13nm to 21nm, the viewing angle characteristic of chromaticity is deteriorated. As described above, it is found that if the thickness t of the electrode layer on the light extraction surface side is increased, the viewing angle characteristics of chromaticity are deteriorated. This is caused by the following reasons: as the film thickness t of the electrode layer on the light extraction surface side becomes thicker, the resonance condition becomes stronger, and the viewing angle characteristics of each color are deviated by interacting with the influence of the wavelength dispersion of the refractive index.

As is clear from fig. 7, reducing the interference level Ma is equivalent to reducing the thickness of the electrode layer on the light extraction surface side.

On the other hand, as is clear from fig. 8, in the light-emitting device 1 of the embodiment, even if the film thickness of the electrode layer on the light extraction surface side is thickened to 21nm, good viewing angle characteristics are obtained. In this case, the resistance value of the electrode layer on the light extraction surface side of the light-emitting device 1 of the example was 0.62 times as high as the resistance value of the electrode layer on the light extraction surface side of the light-emitting device (t 13nm) of the comparative example shown in fig. 6. Therefore, it is understood that the light-emitting device 1 of the embodiment is excellent not only in the viewing angle characteristics but also in the power feeding performance.

As is clear from the above, in the present embodiment, 2 reflective interfaces (third reflective interfaces S3R, S3G, S3B and fourth reflective interfaces S4R, S4G, S4B) are provided outside the cathode electrodes (electrode layers 14R,14G, 14B) of the respective light emitting sections (red light emitting section 10R, green light emitting section 10G, blue light emitting section 10B); and a microcavity structure with the smallest resonance condition is formed by a structure including the first reflective interfaces S1R, S1G, S1B, the second reflective interfaces S2R, S2G, S2B, the third reflective interfaces S3R, S3G, S3B, and the fourth reflective interfaces S4R, S4G, and S4B. Thus, even when the cathode electrodes (electrode layers 14R,14G, and 14B) on the light extraction surfaces SDR, SDG, and SDB side are thick, the deterioration of the viewing angle characteristics of chromaticity can be reduced.

In the present embodiment, the microcavity structure of each light-emitting portion (red light-emitting portion 10R, green light-emitting portion 10G, blue light-emitting portion 10B) is configured such that: the first reflective interfaces S1R, S1G, S1B and the second reflective interfaces S2R, S2G, S2B enhance light in the wavelength band of light emitted from the respective light emitting layers (red light emitting layer 131R, green light emitting layer 131G, blue light emitting layer 131B), and the third reflective interfaces S3R, S3G, S3B and the fourth reflective interfaces S4R, S4G, S4B attenuate light in the wavelength band of light emitted from the respective light emitting layers (red light emitting layer 131R, green light emitting layer 131G) and enhance light in the wavelength band of light emitted from the blue light emitting layer 131B.

thus, red light LR having a gentle peak value can be extracted from light extraction surface SDR in red light emitting unit 10R; the green light emitting unit 10G can extract green light LG having a gradual peak from the light extraction surface SDG; in the blue light emitting section 10B, the blue light LB having a sharp peak can be extracted from the light extraction surface SDB. The result is: when the difference between the effect of the resonator structure of red light emitting unit 10R and green light emitting unit 10G and the effect of the resonator structure of blue light emitting unit 10B is small, the angular dependence of luminance and chromaticity is small. Therefore, both the power supply performance and the viewing angle characteristic of chromaticity can be ensured. In addition, the light-emitting device 1 having high viewing angle characteristics is also suitable for a display device requiring high image quality, and the productivity of the display device can be improved.

In this embodiment, the optical distance between the second reflective interface S2R and the third reflective interface S3R is equal to or less than the center wavelength λ a of the light emitted from the red light-emitting layer 131R. Similarly, the optical distance between the second reflective interface S2G and the third reflective interface S3G is equal to or less than the center wavelength λ b of the light emitted from the green light-emitting layer 131G. The optical distance between the second reflective interface S2B and the third reflective interface S3B is equal to or less than the center wavelength λ c of the light emitted from the blue light-emitting layer 131B. Thus, the peak profiles of the spectra of the light generated in the red light-emitting layers 131R, the green light-emitting layers 131G, and the blue light-emitting layers 131B can be adjusted by the action of the second reflective interfaces S2R, S2G, S2B, the third reflective interfaces S3R, S3G, S3B, and the fourth reflective interfaces S4R, S4G, S4B on the light generated in the light-emitting layers (131R, 131G, and 131B). Therefore, even when the cathode electrodes (electrode layers 14R,14G, and 14B) on the light extraction surfaces SDR, SDG, and SDB side are thick, the deterioration of the viewing angle characteristics of chromaticity can be reduced.

In the present embodiment, the microcavity structure of the red light-emitting portion 10R is configured to satisfy the above-described expressions (1), (2), (7), (8), (13), (14), (19), and (20). Similarly, the microcavity structure of the green light-emitting member 10G is configured to satisfy the above equations (3), (4), (9), (10), (15), (16), (21), and (22). Thus, red light LR having a gentle peak value can be extracted from light extraction surface SDR in red light emitting unit 10R; the green light emitting unit 10G can extract green light LG having a gradual peak from the light extraction surface SDG. As a result, abrupt changes in luminance and chromaticity due to the angle can be suppressed.

In the present embodiment, the microcavity structure of the blue light-emitting part 10B is configured to satisfy the above-described equations (5), (6), (11), (12), (17), (18), (23), and (24). Accordingly, in the blue light emitting unit 10B, the blue light LB having a sharp peak can be extracted from the light extraction surface SDB. Therefore, the difference between the effect of the resonator structure of red light emitting unit 10R and green light emitting unit 10G and the effect of the resonator structure of blue light emitting unit 10B is small, and the angular dependence of luminance and chromaticity is small. Therefore, the light distribution characteristics can be improved. In addition, the light-emitting device 1 having high light distribution characteristics is also suitable for a display device requiring high image quality, and the productivity of the display device can be improved.

in the present embodiment, the thickness of the electrode layers 14R,14G, and 14B is 15nm or more. This can improve power supply performance without impairing the angle dependence of chromaticity. The reason for this will be described with reference to fig. 9 and 10. Fig. 9 shows an example of a change in the film thickness of the electrode on the light extraction surface side from the 45-degree chromaticity viewing angle of the light-emitting device of the comparative example. Fig. 10 shows an example of a change in relative luminance of the light-emitting device of the comparative example to the film thickness of the electrode on the light extraction surface side. Fig. 9 and 10 show the results of using the same light-emitting device as that used in fig. 6. As is clear from fig. 9, in order to reduce the chromaticity to 0.020 or less, the film thickness of the electrode on the light extraction surface side needs to be 15nm or less, and 0.020 is 1 index of the viewing angle dependence. In short, in the light-emitting device of the comparative example, it is very difficult to practically set the film thickness of the electrode on the light extraction surface side to 15nm or more. On the other hand, in the present embodiment, even when the film thickness of the electrode layers 14R,14G, and 14B is set to 15nm or more, the angle dependence of chromaticity is not impaired. However, as shown in fig. 10, if the film thickness of the electrode on the extraction surface side is made larger than 38nm, the luminance becomes lower than when the film thickness of the electrode on the extraction surface side is made 15 nm. Therefore, in the present embodiment, by setting the film thickness of the electrode layers 14R,14G, and 14B to 15nm to 38nm, the angle dependence of luminance and chromaticity is not impaired.

In this embodiment, the substrate 11 is a circuit substrate on which a circuit (the pixel circuit 18-1) for driving the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B is provided. Here, the light emitting device 1 is a top emission type light emitting device. Thus, the light emitted from the red, green, and blue light-emitting layers 131R, 131G, and 131B is not blocked by the pixel circuit 18-1 in the circuit substrate, and therefore, high light extraction efficiency can be obtained.

In this embodiment, the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B are preferably printed layers. The organic layer is likely to have a size due to the thickness of the region through a drying process or the like. That is, the organic layer tends to have a film thickness distribution. On the other hand, in the present embodiment, by using the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B as the printed layer, it is possible to adjust the difference in the effect of the resonator structure of each light-emitting element due to the film thickness distribution of the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B.

<2. modification >

in the following description, the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

In the above embodiment, the electrode layers 14R,14G, and 14B are each formed of a single metal layer having a film thickness of 15nm or more. However, in the above embodiment, the electrode layers 14R,14G, and 14B may be formed of a laminate of a plurality of conductive layers. In the above embodiment, instead of the electrode layer 14R, a laminate 18R may be provided as shown in fig. 11. Similarly, in the above embodiment, instead of the electrode layer 14G, a laminate 18G may be provided as shown in fig. 11. In the above embodiment, instead of the electrode layer 14B, a laminate 18B may be provided as shown in fig. 11.

As shown in fig. 11, the laminate 18R includes a metal layer 181R, a transparent layer 182R, and a metal layer 183R. As shown in fig. 11, the laminate 18G includes a metal layer 181G, a transparent layer 182G, and a metal layer 183G. As shown in fig. 11, the stacked body 18B includes a metal layer 181B, a transparent layer 182B, and a metal layer 183B.

The metal layers 181R,181G,181B are formed of a metal material having a high reflectance. The metal layers 181R,181G, and 181B are formed of, for example, magnesium (Mg), silver (Ag), or an alloy thereof. The metal layers 181R,181G,181B are thicker than the metal layers 183R,183G, 183B. The thickness of the metal layers 181R,181G,181B is, for example, 5nm to 50 nm. When the metal layers 181R,181G, and 181B are formed of such a metal material having a high reflectance, the effect of the resonator structure can be improved, and the light extraction efficiency can be improved. This also makes it possible to suppress power consumption and to extend the life of the red light emitting section 10R, the green light emitting section 10G, and the blue light emitting section 10B.

the transparent layers 182R,182G,182B are formed of a transparent conductor material. Examples of the transparent conductive material used for the transparent layers 182R,182G, and 182B include ito (indium Tin oxide) and Indium Zinc Oxide (IZO). The thickness of the transparent layers 182R,182G,182B is, for example, 30nm to 600 nm. The transparent layer 182R is in contact with the metal layers 181R, 183R. The transparent layer 182G is in contact with the metal layers 181G, 183G. The transparent layer 182B is in contact with the metal layers 181B, 183B.

The metal layers 183R,183G,183B are formed of a metal material having a high reflectance. As the metal materials for the metal layers 183R,183G,183B, there can be mentioned: such as magnesium (Mg), silver (Ag), or alloys thereof, and the like. The total thickness of the metal layers 181R,181G,181B and the metal layers 183R,183G,183B is, for example, 15nm or more. The thickness of the metal layers 183R,183G,183B is, for example, 5nm to 20 nm. The metal layer 183R is electrically connected to the metal layer 181R through the transparent layer 182R. The metal layer 183G is electrically connected to the metal layer 181G through the transparent layer 182G. The metal layer 183B is electrically connected to the metal layer 181B through the transparent layer 182B.

Next, the resonator structure of red light emitting unit 10R, green light emitting unit 10G, and blue light emitting unit 10B will be described.

the red light emitting unit 10R includes, in order from the substrate 11 side: a first reflective interface S1R, a fifth reflective interface S5R, a sixth reflective interface S6R, a third reflective interface S3R, a fourth reflective interface S4R, and a light extraction plane SDR. At this time, a microcavity structure is formed by a structure including the first reflective interface S1R, the fifth reflective interface S5R, the sixth reflective interface S6R, the third reflective interface S3R, and the fourth reflective interface S4R. Between the first reflective interface S1R and the fifth reflective interface S5R, the emission center OR of the red light-emitting layer 131R is disposed. In other words, the red light-emitting layer 131R is provided between the first reflective interface S1R and the light extraction surface SDR which face each other. The fifth reflective interface S5R is the interface between the red organic layer 13R and the metal layer 181R. The sixth reflective interface S6R is the interface of the transparent layer 182R and the metal layer 183R.

The green light emitting section 10G includes, in order from the substrate 11 side: a first reflective interface S1G, a fifth reflective interface S5G, a sixth reflective interface S6G, a third reflective interface S3G, a fourth reflective interface S4G, and a light extraction surface SDG. At this time, a microcavity structure is formed by a structure including the first reflective interface S1G, the fifth reflective interface S5G, the sixth reflective interface S6G, the third reflective interface S3G, and the fourth reflective interface S4G. Between the first reflective interface S1G and the fifth reflective interface S5G, a light emission center OG of the green light-emitting layer 131G is provided. In other words, the green light-emitting layer 131G is provided between the first reflective interface S1G and the light extraction surface SDG, which face each other. The fifth reflective interface S5G is the interface between the green organic layer 13G and the metal layer 181G. The sixth reflective interface S6G is the interface of the transparent layer 182G and the metal layer 183G.

The blue light emitting section 10B includes, in order from the substrate 11 side: a first reflective interface S1B, a fifth reflective interface S5B, a sixth reflective interface S6B, a third reflective interface S3B, a fourth reflective interface S4B, and a light extraction surface SDB. At this time, a microcavity structure is formed by a structure including the first reflective interface S1B, the fifth reflective interface S5B, the sixth reflective interface S6B, the third reflective interface S3B, and the fourth reflective interface S4B. Between the first reflective interface S1B and the fifth reflective interface S5B, the light emission center OB of the blue light-emitting layer 131B is provided. In other words, the blue light-emitting layer 131B is provided between the first reflective interface S1B and the light extraction surface SDB, which face each other. The fifth reflective interface S5B is the interface between the blue organic layer 13B and the metal layer 181B. The sixth reflective interface S6B is the interface of the transparent layer 182B and the metal layer 183B.

the fifth reflective interfaces S5R, S5G, S5B and the sixth reflective interfaces S6R, S6G, S6B are made of a reflective film of metal.

(fifth reflecting interface S5R, S5G, S5B)

The red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B are formed of a material having a refractive index of 1.75, and the metal layers 181R,181G, and 181B are formed of silver (Ag) having a refractive index of 0.13 and an extinction coefficient of 3.96. In this case, the fifth reflective interface S5R is disposed at an optical distance La5 from the light emission center OR, the fifth reflective interface S5G is disposed at an optical distance Lb5 from the light emission center OG, and the fifth reflective interface S5B is disposed at an optical distance Lc5 from the light emission center OB.

The optical distance La5 is set to: by the interference between the fifth reflective interface S5R and the emission center OR, the light of the center wavelength λ a of the emission spectrum of the red light-emitting layer 131R is mutually intensified. The optical distance Lb5 is set to: by the interference between the fifth reflective interface S5G and the light emission center OG, light of the center wavelength λ b of the emission spectrum of the green light-emitting layer 131G is mutually enhanced. The optical distance Lc5 is set to: by the interference between the fifth reflective interface S5B and the light emission center OB, the light of the center wavelength λ c of the emission spectrum of the blue light-emitting layer 131B is mutually intensified.

Specifically, the optical distances La5, Lb5, Lc5 satisfy the following expressions (25) to (30).

λa-80＜λa5＜λa+80……(26)

λb-80＜λb5＜λb+80……(28)

λc-80＜λc5＜λc+80……(30)

Wherein Ha, Hb, Hc: an integer of 0 or more

units of λ a, λ a5, λ b5, λ c 5: nm (length)

φ a 5: the phase change of the light emitted from the red light-emitting layer 131R when reflected by the fifth reflective interface S5R

φ b 5: the phase change of the light emitted from the green light-emitting layer 131G when reflected by the fifth reflective interface S5G

φ c 5: the phase change of the light emitted from the blue light-emitting layer 131B when reflected by the fifth reflective interface S5B

λ a 5: a wavelength satisfying the formula (26)

λ b 5: a wavelength satisfying the formula (28)

λ c 5: a wavelength satisfying the formula (30)

φ a5 can be obtained by the same method. If the values of Ha, Hb, Hc are large, the so-called microcavity (microresonator) effect may not be obtained. For this reason, Ha ═ 0, Hb ═ 0, and Hc ═ 0 are preferable.

Here, Na is 0, Nb is 0, Nc is 0, Ha is 0, Hb is 0, and Hc is 0. In this case, a microcavity structure having the smallest resonance condition is formed by a structure including the first reflective interface S1R, the third reflective interface S3R, the fourth reflective interface S4R, the fifth reflective interface S5R, and the sixth reflective interface S6R. Similarly, a microcavity structure having the smallest resonance condition is formed by a structure including the first reflective interface S1G, the third reflective interface S3G, the fourth reflective interface S4G, the fifth reflective interface S5G, and the sixth reflective interface S6G. Further, a microcavity structure having the smallest resonance condition is formed by a structure including the first reflective interface S1B, the third reflective interface S3B, the fourth reflective interface S4B, the fifth reflective interface S5B, and the sixth reflective interface S6B.

when the optical distance La1 satisfies the above equations (1) and (2) and the optical distance La5 satisfies the above equations (25) and (26), a peak of transmittance occurs at a predetermined wavelength due to the amplification effect of the first reflective interface S1R and the fifth reflective interface S5R. When the optical distance Lb1 satisfies the above equations (3) and (4) and the optical distance Lb5 satisfies the above equations (27) and (28), a peak of transmittance occurs at a predetermined wavelength due to the amplification effect of the first reflective interface S1G and the fifth reflective interface S5G. When the optical distance Lc1 satisfies the above equations (5) and (6) and the optical distance Lc5 satisfies the above equations (29) and (30), a peak of transmittance occurs at a predetermined wavelength due to the amplification effect of the first reflective interface S1B and the fifth reflective interface S5B.

(sixth reflective interface S6R, S6G, S6B)

The optical distance La6 is set to, for example: the light of the center wavelength λ a of the emission spectrum of the red light-emitting layer 131R is attenuated by the interference between the sixth reflective interface S6R and the emission center OR. At this time, the optical distance between the fifth reflective interface S5R and the sixth reflective interface S6R is equal to or less than the center wavelength λ a of the light emitted from the red light-emitting layer 131R. The optical distance Lb6 is set to, for example: the light of the center wavelength λ b of the emission spectrum of the green light-emitting layer 131G is attenuated by the interference between the sixth reflective interface S6G and the light emission center OG. At this time, the optical distance between the fifth reflective interface S5G and the sixth reflective interface S6G is equal to or less than the center wavelength λ b of the light emitted from the green light-emitting layer 131G. The optical distance Lc6 is set to, for example: by the interference between the sixth reflective interface S6B and the light emission center OB, the light of the center wavelength λ c of the emission spectrum of the blue light-emitting layer 131B is mutually intensified. At this time, the optical distance between the fifth reflective interface S5B and the sixth reflective interface S6B is equal to or less than the center wavelength λ c of the light emitted from the blue light-emitting layer 131B.

the optical distances La6, Lb6, Lc6 satisfy the following expressions (31) to (36), for example.

λa-150＜λa6＜λa+150……(32)

λb-150＜λb6＜λb+150……(34)

λc-150＜λc6＜λc+150……(36)

Wherein Fa, Fb, Fc: an integer of 0 or more

Units of λ a, λ a6, λ b6, λ c 6: nm (length)

φ a 6: the phase change of the light emitted from the red light-emitting layer 131R when reflected by the sixth reflective interface S6R

φ b 6: the phase change of the light emitted from the green light-emitting layer 131G when reflected by the sixth reflective interface S6G

φ c 6: the phase change of the light emitted from the blue light-emitting layer 131B when reflected by the sixth reflective interface S6B

λ a 6: a wavelength satisfying the formula (32)

λ b 6: a wavelength satisfying the formula (34)

λ c 6: a wavelength satisfying the formula (36)

φ a6 can be obtained by the same method. When the optical distances La6, Lb6, and Lc6 satisfy the above-described equations (31) to (36), the light emission state of each light-emitting part (red light-emitting part 10R, green light-emitting part 10G, and blue light-emitting part 10B) can be adjusted. By adding the reflection at the sixth reflective interface S6R in this manner, the light generated in the red light-emitting layer 131R can be reduced, and the full width at half maximum of the spectrum can be widened. By adding the reflection at the sixth reflective interface S6G, the light generated in the green light-emitting layer 131G can be reduced, and the full width at half maximum of the spectrum can be broadened. By adding the reflection at the sixth reflective interface S6B, the light generated in the blue light-emitting layer 131B can be enhanced, and the full width at half maximum of the spectrum can be narrowed.

The light-emitting device 1 can be manufactured by forming electrode layers 12R,12G, and 12B, organic layers (red organic layer 13R, green organic layer 13G, and blue organic layer 13B), metal layers 181R,181G, and 181B, transparent layers 182R,182G, and 182B, metal layers 183R,183G, and 183B, transparent layers 15R,15G, and 15B, transparent layers 16R,16G, and 16B, and transparent layers 17R,17G, and 17B in this order on the substrate 11. The red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B may be formed by vapor deposition or printing. In other words, the red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B may be printed layers. The metal layers 181R,181G, and 181B may be formed of a common layer. In this case, the material and thickness of the metal layers 181R,181G,181B are the same. The transparent layers 182R,182G, and 182B may be formed of a common layer. In this case, the material and thickness of the transparent layers 182R,182G,182B are the same. The metal layers 183R,183G, and 183B may be formed of a common layer. In this case, the material and thickness of the metal layers 183R,183G,183B are the same.

[ Effect, Effect ]

In the light-emitting device 1 of the present modification, the drive current is injected into the light-emitting layers (the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B) of the red light-emitting portion 10R, the green light-emitting portion 10G, and the blue light-emitting portion 10B through the electrode layers 12R,12G, and 12B and the stacked bodies 18R, 18G, and 18B. The result is: in each light-emitting layer, the holes and the electrons recombine to generate excitons, thereby emitting light.

The light generated in the red organic layer 13R, for example, is multiply reflected between the first reflective interface S1R and the fourth reflective interface S4R, and is extracted from the light extraction surface SDR. In red light emitting unit 10R, red light LR is extracted from light extraction surface SDR; in the green light emitting part 10G, green light LG is extracted from the light extraction surface SDG; in the blue light emitting section 10B, the blue light LB is extracted from the light extraction surface SDB. By additive color mixing of the red light LR, the green light LG, and the blue light LB, various colors can be displayed.

In the present modification, a microcavity structure having the smallest resonance condition is formed by a structure in which 2 reflective interfaces (third reflective interfaces S3R, S3G, S3B, and fourth reflective interfaces S4R, S4G, S4B) are provided outside the cathode electrodes (laminated bodies 18R, 18G, and 18B) of the light emitting sections (red light emitting section 10R, green light emitting section 10G, and blue light emitting section 10B), and the structure includes first reflective interfaces S1R, S1G, S1B, fifth reflective interfaces S5R, S5G, S5B, sixth reflective interfaces S6R, S6G, S6B, third reflective interfaces S3R, S3G, S3B, fourth reflective interfaces S4R, S4G, and S4B. Accordingly, even when the metal layers 181R,181G, and 181B and the metal layers 183R,183G, and 183B included in the cathode electrodes on the light extraction surfaces SDR, SDG, and SDB sides are thick, the deterioration of the viewing angle characteristics of chromaticity can be reduced.

In the present modification, the microcavity structure of each light-emitting portion (red light-emitting portion 10R, green light-emitting portion 10G, blue light-emitting portion 10B) is configured such that: the first reflective interfaces S1R, S1G, S1B and the fifth reflective interfaces S5R, S5G, S5B enhance light in the wavelength band of light emitted from the respective light emitting layers (the red light emitting layer 131R, the green light emitting layer 131G, the blue light emitting layer 131B), and the third reflective interfaces S3R, S3G, S3B and the fourth reflective interfaces S4R, S4G, S4B attenuate light in the wavelength band of light emitted from the respective light emitting layers (the red light emitting layer 131R, the green light emitting layer 131G) and enhance light in the wavelength band of light emitted from the blue light emitting layer 131B.

Thus, red light LR having a gentle peak value can be extracted from light extraction surface SDR in red light emitting unit 10R; the green light emitting unit 10G can extract green light LG having a gradual peak from the light extraction surface SDG; in the blue light emitting section 10B, the blue light LB having a sharp peak can be extracted from the light extraction surface SDB. The result is: when the difference between the effect of the resonator structure of red light emitting unit 10R and green light emitting unit 10G and the effect of the resonator structure of blue light emitting unit 10B is small, the angular dependence of luminance and chromaticity is small. Therefore, both the power supply performance and the viewing angle characteristic of chromaticity can be ensured. In addition, the light-emitting device 1 having high viewing angle characteristics is also suitable for a display device requiring high image quality, and the productivity of the display device can be improved.

In the present modification, the optical distance between the fifth reflective interface S5R and the sixth reflective interface S6R is equal to or less than the center wavelength λ a of the light emitted from the red light-emitting layer 131R. Similarly, the optical distance between the fifth reflective interface S5G and the sixth reflective interface S6G is equal to or less than the center wavelength λ b of the light emitted from the green light-emitting layer 131G. The optical distance between the fifth reflective interface S5B and the sixth reflective interface S6B is equal to or less than the center wavelength λ c of the light emitted from the blue light-emitting layer 131B. Thus, the peak profiles of the spectra of the light generated in the red light-emitting layers 131R, the green light-emitting layers 131G, and the blue light-emitting layers 131B can be adjusted by the action of the fifth reflective interfaces S5R, S5G, and S5B and the sixth reflective interfaces S6R, S6G, and S6B on the light generated in the light-emitting layers (131R, 131G, and 131B). Therefore, even when the cathode electrodes (electrode layers 14R,14G, and 14B) on the light extraction surfaces SDR, SDG, and SDB side are thick, the deterioration of the viewing angle characteristics of chromaticity can be reduced.

In the present modification, the microcavity structure of the red light-emitting portion 10R is configured to satisfy the above-described expressions (1), (2), (25), (26), (31), (32), (19), and (20). Similarly, the microcavity structure of green light-emitting member 10G is configured to satisfy expressions (3), (4), (27), (28), (33), (34), (21), and (22). Thus, red light LR having a gentle peak value can be extracted from light extraction surface SDR in red light emitting unit 10R; the green light emitting unit 10G can extract green light LG having a gradual peak from the light extraction surface SDG. As a result, abrupt changes in luminance and chromaticity due to the angle can be suppressed.

In the present modification, the microcavity structure of the blue light-emitting portion 10B is configured to satisfy the above-described equations (5), (6), (29), (30), (35), (36), (23), and (24). Accordingly, in the blue light emitting unit 10B, the blue light LB having a sharp peak can be extracted from the light extraction surface SDB. Therefore, the difference between the effect of the resonator structure of red light emitting unit 10R and green light emitting unit 10G and the effect of the resonator structure of blue light emitting unit 10B is small, and the angular dependence of luminance and chromaticity is small. Therefore, the light distribution characteristics can be improved. In addition, the light-emitting device 1 having high light distribution characteristics is also suitable for a display device requiring high image quality, and the productivity of the display device can be improved.

In the present modification, the total thickness of the metal layers 181R,181G,181B and the metal layers 183R,183G,183B is, for example, 15nm or more. This can improve power supply performance without impairing the angle dependence of chromaticity. In the present modification, similarly to the above embodiment, by setting the total thickness of the metal layers 181R,181G,181B and the metal layers 183R,183G,183B to 15nm to 38nm, the angle dependence of luminance and chromaticity is not impaired.

in the present modification, the substrate 11 is a circuit substrate on which a circuit (pixel circuit 18-1) for driving the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B is provided. Here, the light emitting device 1 is a top emission type light emitting device. Thus, the light emitted from the red, green, and blue light-emitting layers 131R, 131G, and 131B is not blocked by the pixel circuit 18-1 in the circuit substrate, and therefore, high light extraction efficiency can be obtained.

In the present modification, the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B are preferably printed layers. The organic layer is likely to have a size due to the thickness of the region through a drying process or the like. That is, the organic layer tends to have a film thickness distribution. In the present modification, the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B are formed as a printed layer, whereby it is possible to adjust the difference in the effect of the resonator structure of each light-emitting element due to the film thickness distribution of the red light-emitting layer 131R, the green light-emitting layer 131G, and the blue light-emitting layer 131B.

<3. application example >

Next, an application example of the light-emitting device 1 described in the above embodiment and the like will be described.

[ application example A ]

fig. 12 shows a schematic configuration example of a display device 2 as an application example of the light-emitting device 1 according to the above-described embodiment and its modified example. Fig. 13 shows an example of a circuit configuration of each pixel 18 provided in the display device 2. The display device 2 includes, for example, the light-emitting device 1, a controller 20, and a driver 30. The driver 30 is mounted, for example, on an outer peripheral portion of the light-emitting device 1. The light-emitting device 1 has a plurality of pixels 18 arranged in a matrix shape. The controller 20 and the driver 30 drive the light emitting device 1 (the plurality of pixels 18) based on the video signal Din and the synchronization signal Tin input from the outside.

(light-emitting device 1)

The light emitting device 1 displays an image based on a video signal Din and a synchronization signal Tin input from the outside by performing active matrix driving on each pixel 18 by the controller 20 and the driver 30. The light-emitting device 1 includes: a plurality of scanning lines WSL and a plurality of power supply lines DSL extending in the row direction, a plurality of signal lines DTL extending in the column direction, and a plurality of pixels 18 arranged in a matrix shape.

The scanning line WSL is used for selection of each pixel 18, and supplies a selection pulse that selects each pixel 18 in each predetermined unit (for example, pixel row) to each pixel 18. The signal line DTL is used to supply a signal voltage Vsig corresponding to the picture signal Din to each pixel 18, and to supply a data pulse containing the signal voltage Vsig to each pixel 18. The power supply line DSL supplies power to each pixel 18.

The plurality of pixels 18 provided in the light emitting device 1 include: a pixel 18 emitting red light, a pixel 18 emitting green light, and a pixel 18 emitting blue light. Hereinafter, the pixel 18 emitting red light is referred to as a pixel 18r, the pixel 18 emitting green light is referred to as a pixel 18g, and the pixel 18 emitting blue light is referred to as a pixel 18 b. Among the plurality of pixels 18, the pixels 18r, 18g, and 18b constitute display pixels which are display units of color images. Each display pixel may further include a pixel 18 emitting another color (for example, white or yellow). Therefore, the plurality of pixels 18 provided in the light emitting device 1 are grouped as display pixels by a predetermined number. In each display pixel, the plurality of pixels 18 are arranged in a row in a predetermined direction (for example, a row direction).

Each signal line DTL is connected to an output terminal of a horizontal selector 31 described later. For each pixel column, for example, 1 of the plurality of signal lines DTL is allocated. Each scanning line WSL is connected to an output terminal of a write scanner 32 described later. For each pixel row, for example, 1 of the plurality of scanning lines WSL is allocated. Each power line DSL is connected to an output of the power supply. For each pixel row, for example, 1 of the plurality of power supply lines DSL is allocated.

Each pixel 18 has a pixel circuit 18-1 and an organic electroluminescent portion 18-2. The organic electroluminescence light emitting part 18-2 corresponds to the light emitting parts (e.g., the red light emitting part 10R, the green light emitting part 10G, and the blue light emitting part 10B) of the above-described embodiment and the modifications thereof.

The pixel circuit 18-1 controls light emission and extinction of the organic electroluminescence light emitting section 18-2. The pixel circuit 18-1 has a function of holding a voltage written to each pixel 18 by write scanning. The pixel circuit 18-1 is configured to include, for example, a drive transistor Tr1, a write transistor Tr2, and a storage capacitor Cs.

The write transistor Tr2 applies a signal voltage Vsig corresponding to the picture signal Din to the gate control of the drive transistor Tr 1. Specifically, the write transistor Tr2 samples the voltage of the signal line DTL, and writes the sampled voltage to the gate of the drive transistor Tr 1. The drive transistor Tr1 is connected in series to the organic electroluminescence light emitting portion 18-2. The drive transistor Tr1 drives the organic electroluminescence light emitting section 18-2. The drive transistor Tr1 controls the current flowing into the organic electroluminescent section 18-2 according to the magnitude of the voltage sampled by the write transistor Tr 2. The storage capacitor Cs is used to maintain a predetermined voltage between the gate-source of the drive transistor Tr 1. The storage capacitor Cs has a function of keeping a constant voltage Vgs between the gate and the source of the driving transistor Tr1 for a predetermined period. The pixel circuit 18-1 may have a circuit configuration in which various capacitors and transistors are added to the circuit of the 2Tr1C, or may have a circuit configuration different from the circuit configuration of the 2Tr 1C.

each signal line DTL is connected to an output terminal of the horizontal selector 31 and a source or a drain of the write transistor Tr2, which will be described later. Each scanning line WSL is connected to an output terminal of the write scanner 32 and a gate of the write transistor Tr2, which will be described later. Each power line DSL is connected to the source or drain of the power circuit and drive transistor Tr 1.

the gate of the write transistor Tr2 is connected to the scanning line WSL. The source or drain of the write transistor Tr2 is connected to the signal line DTL. Of the source and drain of the write transistor Tr2, a terminal not connected to the signal line DTL is connected to the gate of the drive transistor Tr 1. The source or drain of the drive transistor Tr1 is connected to the power supply line DSL. The terminal of the source and the drain of the drive transistor Tr1, which is not connected to the power supply line DSL, is connected to the anode 21 of the organic electroluminescent portion 18-2. One end of the storage capacitor Cs is connected to the gate of the drive transistor Tr 1. The other end of the storage capacitor Cs is connected to the terminal on the organic electroluminescence light emitting section 18-2 side in the source and drain of the drive transistor Tr 1.

(driver 30)

The driver 30 has, for example, a horizontal selector 31 and a write scanner 32. The horizontal selector 31 applies an analog signal voltage Vsig input from the controller 20 to each signal line DTL in response to input of a (synchronous) control signal, for example. The write scanner 32 scans the plurality of pixels 18 at each of the desired locations.

(controller 20)

Next, the controller 20 will be explained. The controller 20 performs predetermined correction on the digital picture signal Din input from the outside, for example, and generates a signal voltage Vsig from the picture signal obtained thereby. The controller 20 outputs the generated signal voltage Vsig to the horizontal selector 31, for example. The controller 20 outputs control signals to the respective circuits in the driver 30 in response to (in synchronization with) a synchronization signal Tin input from the outside, for example.

In this application example, the light-emitting device 1 is used as a display panel for displaying an image. Thus, even when the light-emitting device 1 is large, the display device 2 having excellent display quality with little angle dependence of luminance and chromaticity can be provided.

[ application example B ]

The display device 2 of application example a described above can be applied to various types of electronic apparatuses. Fig. 14 shows a three-dimensional structure of an electronic device 3 to which the display device 2 of application example a is applied. The electronic device 3 is, for example, a sheet-like personal computer having a display surface 320 on a main surface of a casing 310. The electronic device 3 includes the display device 2 of application example a on the display surface 320 thereof, and the display device 2 of application example a is disposed so that the image display surface faces the outside. In the present application example, since the display device 2 of the application example a is provided on the display surface 320, the electronic apparatus 3 having excellent display quality with little angle dependence of luminance and chromaticity can be provided even when the display surface 320 is large.

[ application example C ]

Hereinafter, an application example of the light-emitting device 1 of the above embodiment and its modified example will be described. The light-emitting device 1 of the above-described embodiment and its modified examples can be applied to light sources of lighting devices in all fields such as a desk-top lighting device, a floor-standing lighting device, and an indoor lighting device.

Fig. 15 shows an external appearance of an indoor lighting device to which the light emitting device 1 according to the above-described embodiment and the modification thereof is applied. The lighting device includes, for example, a lighting unit 410 configured to include the light emitting device 1 according to the above-described embodiment and its modified example. The lighting units 410 are disposed on the ceiling 420 of the building at appropriate numbers and intervals. The illumination unit 410 is not limited to be provided on the ceiling 420 depending on the application, and may be provided on any place such as a wall 430 or a floor (not shown).

In these lighting devices, light from the light emitting device 1 of the above embodiment and its modified example is used for lighting. Thus, an illumination device with high illumination quality and little angle dependence of luminance and chromaticity can be obtained.

Although the present disclosure has been described above by way of examples of the embodiments and applications, the present disclosure is not limited to the embodiments and the like, and various changes may be made. The effects described in this specification are merely examples. The effects of the present disclosure are not limited to the effects described in the present specification. The present disclosure may have effects other than those described in the present specification.

In addition, the present disclosure can also adopt the following configuration.

(1)

A light-emitting device is provided with:

A plurality of organic electroluminescence light emitting parts each including a first electrode layer, an organic light emitting layer, a second electrode layer having a film thickness of 15nm or more, and a reflective layer in this order; and

A light extraction surface that extracts light emitted from each of the organic electroluminescence light emitting parts through the reflection layer,

The reflective layer comprises 2 reflective interfaces and,

In each of the organic electroluminescent units, a microcavity structure is formed by a structure including a first reflective interface on the organic light emitting layer side of the first electrode layer, a second reflective interface on the organic light emitting layer side of the second electrode layer, and 2 reflective interfaces included in the reflective layer,

The plurality of organic electroluminescence light emitting portions include a plurality of first organic electroluminescence light emitting portions that emit light in a first wavelength band and a plurality of second organic electroluminescence light emitting portions that emit light in a second wavelength band having a wavelength smaller than the first wavelength band,

In each of the first organic electroluminescence light emitting portion and the second organic electroluminescence light emitting portion, the first reflection interface and the second reflection interface of the microcavity structure are configured to enhance light in each of the first wavelength band and the second wavelength band, and the 2 reflection interfaces included in the reflection layer of the microcavity structure are configured to attenuate light in the first wavelength band and enhance light in the second wavelength band.

(2)

The light-emitting device according to the item (1), wherein,

The optical distance between the second reflecting interface and 2 reflecting interfaces contained in the reflecting layer is less than or equal to the central wavelength of light emitted from the corresponding organic light-emitting layer.

(3)

The light-emitting device of (1) or (2), wherein,

The microcavity structure is a microcavity structure in which a resonance condition is minimum.

(4)

The light-emitting device according to the item (3), wherein,

the microcavity structure is configured so as to satisfy the following expressions (a) to (H) in each of the first organic electroluminescent unit and the second organic electroluminescent unit,

λa-150＜λa1＜λa+80……(B)

λa-80＜λa2＜λa+80……(D)

λa-150＜λa3＜λa+150……(F)

λa-150＜λa4＜λa+150……(H)

La 1: an optical distance between the first reflective interface and a light-emitting center of the organic light-emitting layer of the first organic electroluminescent section;

La 2: an optical distance between the second reflective interface and a light-emitting center of the organic light-emitting layer of the first organic electroluminescent section;

La 3: an optical distance from an emission center of the organic emission layer of the first organic electroluminescence section to one of 2 reflective interfaces included in the reflective layer;

la 4: an optical distance from an emission center of the organic light emitting layer of the first organic electroluminescence light emitting section to another one of the 2 reflective interfaces included in the reflective layer;

φ a 1: in the first organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when reflected by the first reflective interface changes;

φ a 2: in the first organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when reflected by the second reflection interface changes;

φ a 3: in the first organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when one of the 2 reflection interfaces included in the reflection layer is reflected changes;

φ a 4: in the first organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when the light is reflected by another one of the 2 reflective interfaces included in the reflective layer is changed;

λ a: a center wavelength of an emission spectrum of the organic light emitting layer of the first organic electroluminescence light emitting part;

λ a 1: a wavelength satisfying formula (B);

λ a 2: a wavelength satisfying formula (D);

λ a 3: a wavelength satisfying formula (F);

λ a 4: a wavelength satisfying formula (H);

Ka. And Ja: an integer of 0 or more.

(5)

The light-emitting device according to the item (4), wherein,

the microcavity structure is configured so as to satisfy the following formulas (I) to (P) in each of the first organic electroluminescent unit and the second organic electroluminescent unit,

λc-150＜λc1＜λc+80……(J)

λc-80＜λc2＜λc+80……(L)

λc-150＜λc3＜λc+150……(N)

λc-150＜λc4＜λc+150……(P)

Lc 1: an optical distance between the first reflective interface and a light-emitting center of the organic light-emitting layer of the second organic electroluminescent section;

Lc 2: an optical distance between the second reflective interface and a light-emitting center of the organic light-emitting layer of the second organic electroluminescence light-emitting part;

lc 3: an optical distance between one of the 2 reflective interfaces included in the reflective layer and an emission center of the organic light-emitting layer of the second organic electroluminescent section;

Lc 4: an optical distance from an emission center of the organic light emitting layer of the second organic electroluminescence section to another one of the 2 reflective interfaces included in the reflective layer;

φ c 1: in the second organic electroluminescent section, a phase of light emitted from the organic light-emitting layer when reflected by the first reflective interface changes;

φ c 2: in the second organic electroluminescent section, a phase of light emitted from the organic light-emitting layer when reflected by the second reflective interface changes;

φ c 3: in the second organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when one of the 2 reflection interfaces included in the reflection layer is reflected is changed;

φ a 4: in the second organic electroluminescence portion, a phase of light emitted from the organic light emitting layer when the light is reflected by another one of the 2 reflective interfaces included in the reflective layer is changed;

λ c: a center wavelength of an emission spectrum of the organic light emitting layer of the second organic electroluminescence light emitting part;

λ c 1: a wavelength satisfying formula (J);

λ c 2: a wavelength satisfying formula (L);

λ c 3: a wavelength satisfying formula (N);

λ c 4: a wavelength satisfying formula (P);

Kc. Jc: an integer of 0 or more.

(6)

the light-emitting device of any one of the (1) to (5), wherein,

the second electrode layer is formed of a single metal layer having a film thickness of 15nm or more.

(7)

The light-emitting device of any one of the (1) to (5), wherein,

The second electrode layer includes a first metal layer, a transparent conductor layer, and a second metal layer in this order from the organic light emitting layer side,

The total thickness of the first metal layer and the second metal layer is greater than or equal to 15 nm.

(8)

The light-emitting device according to the above (7), wherein,

The first metal layer is thicker than the second metal layer.

(9)

The light-emitting device of any one of the (1) to (8), wherein,

a circuit board on which a drive circuit for driving each of the organic electroluminescence light emitting parts is formed is further provided on a side opposite to the light extraction surface due to a positional relationship with each of the organic electroluminescence light emitting parts.

(10)

the light-emitting device of any one of the (1) to the (9), wherein,

The organic light emitting layer is a printed layer.

This disclosure contains subject matter relating to the disclosure in japanese priority patent application JP2018-102520 filed at 29.5.2018 at the japan patent office, the entire contents of which are incorporated herein by reference.

It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible in light of design requirements and other factors, but are included within the scope of the appended claims or their equivalents.