阅读说明：本技术 电致变色装置 (Electrochromic device ) 是由 金容赞 金起焕 曹弼盛 于 2018-04-23 设计创作，主要内容包括：本申请涉及电致变色装置。所述电致变色装置具有同时具有反射性和光吸收特性的导电层。根据本申请的装置能够实现各种美感、色感或立体色彩图案,并且同时具有优异的耐久性。(The present application relates to electrochromic devices. The electrochromic device has a conductive layer having both reflective and light absorbing properties. The device according to the present application can realize various aesthetic feelings, color senses or three-dimensional color patterns, and at the same time, has excellent durability.)

1. A reflective electrochromic device comprising a conductive layer comprising a metal oxide, metal nitride, or metal oxynitride; an electrochromic layer; an electrolyte layer; and a light-transmitting counter electrode layer.

2. The reflective electrochromic device of claim 1, wherein the conductive layer is a single layer of a metal oxide, metal nitride, or metal oxynitride.

3. The reflective electrochromic device of claim 1, wherein the conductive layer comprises an oxide, nitride, or oxynitride comprising one or more metals selected from molybdenum (Mo), titanium (Ti), aluminum (Al), and copper (Cu).

4. The reflective electrochromic device of claim 3, wherein the conductive layer comprises CuO_xN_y(0≤x≤1，0≤y≤1，x+y＞0)；MoTi_aO_xN_y(0<a≤2，0≤x≤3，0≤y≤2，x+y>0) (ii) a Or AlO satisfying the following relational expression_xN_y(0≤x≤1.5，0≤y≤1，x+y>0)：

[ relational expression ]

Wherein, in AlO_xN_yWherein x and y mean the ratio of the number of atoms of O and N to one atom of Al, respectively, and in the above-mentioned relational expression, based on AlO_xN_ySaid (aluminum element content) represents an element content (atomic%) of Al, said (oxygen element content) represents an element content (atomic%) of O, and said (nitrogen element content) represents an element content (atomic%) of N.

5. The reflective electrochromic device of claim 1, wherein a thickness of the conductive layer is in a range of 5nm to 500 nm.

6. The reflective electrochromic device of claim 5, wherein the conductive layer has a thickness gradient.

7. The reflective electrochromic device of claim 5, wherein the conductive layer has an unevenness.

8. The reflective electrochromic device of claim 5, wherein the conductive layer has a pattern.

9. The reflective electrochromic device of claim 1, wherein the extinction coefficient of the conductive layer is from 0.2 to 2.5.

10. The reflective electrochromic device of claim 1, wherein the conductive layer has a specific resistance of 5 x 10^-4Omega cm or less.

11. The reflective electrochromic device of claim 1, wherein the electrochromic layer comprises a reductive electrochromic material or an oxidative electrochromic material.

12. The reflective electrochromic device of claim 1, wherein the reductive electrochromic material comprises an oxide of Ti, Nb, Mo, Ta, or W, and

The oxidative electrochromic material comprises one or more from the following: oxides of Cr, Mn, Fe, Co, Ni, Rh or Ir; hydroxides of Cr, Mn, Fe, Co, Ni, Rh or Ir; and prussian blue.

13. The reflective electrochromic device of claim 11, further comprising an ion storage layer between the electrolyte layer and the light transmissive counter electrode layer, wherein the ion storage layer comprises an electrochromic material having different coloration characteristics than the electrochromic material comprised in the electrochromic layer.

14. The reflective electrochromic device of claim 1, further comprising a passivation layer between the conductive layer and the electrochromic layer, wherein the passivation layer comprises a transparent conductive oxide.

15. An apparatus comprising an electrochromic device according to any one of claims 1 to 14.

Technical Field

Cross Reference to Related Applications

The present application claims the benefit based on the priority of korean patent application No. 10-2017-0054316 filed on 27.4.2017 and korean patent application No. 10-2018-0045414 filed on 19.4.2018, the disclosures of which are incorporated herein by reference in their entireties.

Background

Electrochromic refers to a phenomenon in which optical characteristics of an electrochromic material are changed by an electrochemical oxidation or reduction reaction, wherein a device using the phenomenon is referred to as an electrochromic device. Electrochromic devices typically include a working electrode, a counter electrode, and an electrolyte, where the optical properties of each electrode can be reversibly changed by an electrochemical reaction. For example, the working electrode or the counter electrode may contain a transparent conductive material and an electrochromic material, respectively, in the form of a device, and in the case where an electric potential is applied to the device, a change in optical characteristics of the electrochromic material occurs as electrolyte ions are inserted into or removed from the device containing the electrochromic material and electrons are simultaneously moved via an external circuit.

The general electrochromic device partially fails to satisfy market demands for various colors or excellent aesthetic sense because the color achieved by the device depends only on the electrochromic material.

Disclosure of Invention

Technical problem

It is an object of the present application to provide a reflective electrochromic device capable of implementing various color senses or stereoscopic color patterns.

It is another object of the present application to provide a reflective electrochromic device having excellent durability.

The above objects and other objects of the present application are all solved by the present application as described in detail below.

Technical scheme

In one example of the present application, the present application relates to an electrochromic device. The electrochromic device is a so-called "reflective" electrochromic device, the constitution of which is different from that of a general transmissive electrochromic device including light-transmissive electrode materials and light-transmissive substrates on both side surfaces of the device. In particular, according to one embodiment of the present application, the present application may use a conductive layer having both light absorption characteristics and reflective, rather than light transmissive, characteristics. The conductive layer having light absorption characteristics provides excellent aesthetic and color realization characteristics to the electrochromic device. For example, in the case of a conventional electrochromic element including only a configuration corresponding to the electrochromic layer, the change in the optical characteristics of the element generally depends on the inherent color itself exhibited by the electrochromic material. However, the device of the present application, which includes a conductive layer having both reflectivity and absorptivity to light in addition to the electrochromic layer, may provide additional optical characteristic changes in addition to the color change caused by the electrochromic layer.

The reflective electrochromic device of the present application may sequentially include a conductive layer, an electrochromic layer, an electrolyte layer, and a light-transmissive counter electrode layer.

In one example, the conductive layer is a light absorbing layer having a light absorbing property more excellent than a light transmitting property, and at the same time, it may have a property of a reflective layer having a reflectivity lower than that of a metal but having a suitable reflectivity. The conductive layer may transform, adjust or change the color or color perception exhibited by the colored or bleached electrochromic layer. Such transformation, adjustment or alteration is believed to be accomplished by optical interference of the conductive layers. In particular, the conductive layer of the present application absorbs light on both the incident path and the reflected path of light due to its light absorbing properties. Furthermore, since the conductive layer has appropriate reflectivity, reflection occurs both on the surface of the conductive layer and at the interface with an adjacent layer. Thus, additional color change or aesthetics can be added by constructive and destructive interference occurring between the reflected light. Thus, the electrochromic device of the present application may allow a user to view a color, color perception, or color pattern that is different from the colors represented in the electrochromic layer.

The conductive layer may comprise a metal oxide, a metal nitride or a metal oxynitride. In one example, the conductive layer may have a single-layer structure including a metal oxide, a metal nitride, or a metal oxynitride. The conductive layer comprising the material may have suitable light absorption characteristics and reflectivity. In consideration of the reflection characteristics of the conductive layer and its interference effect, it may be considered to use a pure metal as the conductive layer material, but the pure metal material has a large degree of deterioration due to electrolyte ions, so that the durability of the element may be reduced.

In one example, the conductive layer may include an oxide, nitride, or oxynitride of one or more metals including nickel (Ni), chromium (Cr), iron (Fe), cobalt (Co), titanium (Ti), vanadium (V), aluminum (Al), gold (Au), copper (Cu), silver (Ag), molybdenum (Mo), and alloys thereof. More specifically, the conductive layer may include a nitride or oxynitride containing one or more selected from molybdenum (Mo), titanium (Ti), aluminum (Al), and copper (Cu).

In one example, the conductive layer may include CuO_xN_y(x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, and x + y is more than or equal to 0). At this time, x and y may mean the ratio of the number of atoms of oxygen (O) and nitrogen (N) to one atom of copper (Cu), respectively.

In another example, the conductive layer may comprise a nitride or oxynitride containing both molybdenum and titanium. More specifically, the conductive layer may comprise MoTi_aO_xN_y(a is more than 0 and less than or equal to 2, x is more than or equal to 0 and less than or equal to 3, y is more than or equal to 0 and less than or equal to 2, and x + y is more than 0). At this time, a, x and y mean the ratio of the number of atoms of titanium (Ti), oxygen (O) and nitrogen (N) to one atom of molybdenum (Mo), respectively.

In another example, the conductive layer may include a nitride or oxynitride of aluminum (Al). More specifically, the conductive layer may contain AlO satisfying the following relational expression_xN_y(0≤x≤1.5，0≤y≤1，x+y＞0)。

[ relational expression ]

However, in AlO_xN_yIn (a), x and y mean the ratio of the number of atoms of O and N to one atom of Al, respectively. Thus, in the above relation, AlO is based on_xN_yThe total element content of 100% (aluminum element content) represents the element content (atomic%) of Al, (oxygen element content) represents the element content (atomic%) of O, and (nitrogen element content) represents the element content (atomic%) of N.

The above relation is an equation in consideration of the element content (atomic%) and the valence as measured by XPS (X-ray photoelectron spectroscopy). The valence of Al is 3, the valence of O is 2, and the valence of N is 3. When the value of the above relation is more than 1, it means that Al is enriched among Al, O and N; and when the value is 1 or less, it means that Al is deficient in Al, O and N. For example, Al₂O₃Or AlN stoichiometrically represents a relatively transparent phase, and the value of the relation is 1. In such a case, it is difficult to perform the above function of the conductive layer. On the other hand, if the value obtained in the above relational expression is greater than 2, the content of Al becomes higher and the metal characteristics become strong, so that the reflectivity becomes high and it becomes difficult to perform the above function of the conductive layer.

The thickness of the conductive layer may be in the range of 5nm to 500nm, without particular limitation. In this application, "thickness" may mean "the normal distance between any point on the layer that meets the normal and the opposite surface point of the relevant layer" or "the average normal distance between one side of the layer of measurement objects and the other side facing that side" when the virtual normal is drawn from the ground towards the device.

In another example, the conductive layer may have a bent portion or an uneven portion. The sectional shape of the curved portion or the uneven portion is not particularly limited, and may be, for example, a portion of a circle, or a portion of a triangle or a quadrangle. When the bent portions or the uneven portions are repeated, interference of various paths may occur, so that the conductive layer may impart various color patterns to the electrochromic device.

In another example, one side of the conductive layer may have a regular or irregular pattern. The form of the pattern is not particularly limited. By the regular or irregular pattern, interference of various paths can occur in the conductive layer, and thus the conductive layer can impart various color patterns to the electrochromic device.

In one example, the refractive index of the conductive layer may be in a range of 0 to 3.

In one example, the extinction coefficient value k of the conductive layer may be in a range of 0.2 to 2.5. More specifically, the extinction coefficient of the conductive layer may be in the range of 0.2 to 1.5 or 0.2 to 0.8. The extinction coefficient k, also referred to as the absorption coefficient, is a measure used to determine how much light or radiation of a particular wavelength can be absorbed by the structure. For example, when k is less than 0.2, it is transparent, so that the degree of light absorption is insignificant. In contrast, when the content of the metal component of the conductive layer is increased, the reflection characteristic becomes dominant, and the k value becomes greater than 2.5. With an extinction coefficient within the above range, the conductive layer has appropriate light absorption characteristics and reflectivity, so that a desired interference effect can be effectively performed in the present application.

In one example, the conductive layer may have a specific resistance of 5 × 10^-4Omega cm or less. When it has a specific resistance within the above range, the electrochromic rate can be improved. In the present specification, the resistance, specific resistance or sheet resistance can be measured using a known surface resistor according to the four-point probe method. The sheet resistance is obtained by measuring a current (I) and a voltage (V) with four probes to determine a resistance value (V/I), then calculating the sheet resistance (V/I × W/L) using the area (sectional area, W) of the sample and the distance (L) between electrodes for measuring the resistance, and multiplying it by a Resistance Correction Factor (RCF) for calculation with ohm/square as a unit of the sheet resistance. The resistance correction factor may be calculated using the size of the sample, the thickness of the sample, and the temperature at the time of measurement, which may be calculated by Poisson's equation. The sheet resistance of the entire laminated body can be measured and calculated in the laminated body itself, and the sheet resistance of each layer can be measured before forming a layer made of the remaining material in the entire laminated body except for the target layer to be measured, and can be measured in the entire laminated body except for the target layer to be measuredThe measurement may be performed after a layer made of the remaining material other than the layer, or may be performed after analyzing the material of the target layer and forming the layer under the same condition as the target layer.

The method of providing the conductive layer is not particularly limited. For example, the conductive layer can be formed using a known wet method or dry method. More specifically, the conductive layer may be formed using sputtering, CVD (chemical vapor deposition), or electron beam (e-beam).

The electrochromic layer may comprise an electrochromic material whose optical properties (i.e., color) are changed by a reversible redox reaction. The kind of electrochromic material is not particularly limited.

In one example, the electrochromic layer may comprise a reducing electrochromic material that is colored upon a reduction reaction. The type of the reductive electrochromic material is not particularly limited, but for example, the reductive electrochromic material may be an oxide of Ti, Nb, Mo, Ta, or W, such as WO₃、MoO₃、Nb₂O₅、Ta₂O₅Or TiO₂。

In another example, the electrochromic layer may comprise a material having different coloring characteristics than the reductive electrochromic material, i.e., an oxidative electrochromic material. The type of the oxidative electrochromic material is also not particularly limited, but for example, the oxidative electrochromic material may be one or more materials selected from the group consisting of: oxides of Cr, Mn, Fe, Co, Ni, Rh or Ir, e.g. LiNiOx, IrO₂、NiO、V₂O₅、LixCoO₂、Rh₂O₃Or CrO₃(ii) a Hydroxides of Cr, Mn, Fe, Co, Ni, Rh or Ir; and prussian blue.

The electrochromic layer may be provided using known methods such as various types of wet coating methods or dry coating methods.

The thickness of the electrochromic layer may be in the range of 30nm to 500nm, without particular limitation.

The electrolyte layer is a structure for supplying electrolyte ions participating in an electrochromic reaction to the electrochromic layer. The type of electrolyte is not particularly limited. For example, a liquid electrolyte, a gel polymer electrolyte, or an inorganic solid electrolyte may be used without limitation.

The specific composition of the electrolyte for the electrolyte layer is not particularly limited as long as it can provide electrolyte ions participating in electrochromism of the electrochromic layer or an ion storage layer to be described below. In one example, the electrolyte layer may contain a material capable of providing electrolyte ions such as H⁺、Li⁺、Na⁺、K⁺、Rb⁺Or Cs⁺The metal salt of (1). More specifically, the electrolyte layer may comprise a lithium salt compound, such as LiClO₄、LiBF₄、LiAsF₆Or LiPF₆(ii) a Or sodium salt compounds, e.g. NaClO₄。

In one example, the electrolyte layer may further include a carbonate compound as a solvent. Since the carbonate-based compound has a high dielectric constant, ion conductivity can be improved. As a non-limiting example, a solvent such as PC (propylene carbonate), EC (ethylene carbonate), DMC (dimethyl carbonate), DEC (diethyl carbonate), or EMC (ethyl methyl carbonate) may be used as the carbonate-based compound.

The counter electrode layer may have a light transmitting property. In the present application, the "light transmission characteristics" may mean, for example, a case where the transmittance to visible light is 60% or more, specifically, 60% to 95%. At this time, the visible light may mean light in a wavelength range of 380nm to 780nm, specifically, light having a wavelength of about 550 nm. The transmittance may be measured by a known method or device such as a haze meter or the like. The transmittance may be applied to the electrolyte layer as well.

The kind of material that can be used for the counter electrode layer is not particularly limited as long as it has a light-transmitting property. For example, a transparent conductive oxide having a light transmitting property, or a metal mesh, or an OMO (oxide/metal/oxide) may be used for the counter electrode layer. At this time, since the OMO can provide a lower sheet resistance than the transparent conductive oxide typified by ITO, it can contribute to an improvement in the color conversion speed of the element.

As useful as a counter electrode layerAs the transparent conductive oxide of (2), for example, ITO (indium tin oxide) and In can be used₂O₃(indium oxide), IGO (indium gallium oxide), FTO (fluorine doped tin oxide), AZO (aluminum doped zinc oxide), GZO (gallium doped zinc oxide), ATO (antimony doped tin oxide), IZO (indium doped zinc oxide), NTO (niobium doped titanium oxide), or ZnO (zinc oxide).

The metal mesh that may be used for the counter electrode layer may have a lattice form including Ag, Cu, Al, Mg, Au, Pt, W, Mo, Ti, Ni, or an alloy thereof. However, materials that can be used for the metal mesh are not limited to the above-listed metal materials.

The OMO that may be used for the counter electrode layer may include an upper layer, a lower layer, and a metal layer therebetween. In one example, the upper and lower layers may include an oxide of one or more metals selected from Sb, Ba, Ga, Ge, Hf, In, La, Se, Si, Ta, Se, Ti, V, Y, Zn, and Zr. Further, the metal layer of the OMO may contain a metal such as Ag, Cu, Zn, Au, or Pd.

without particular limitation, the thickness of the counter electrode layer may be 50nm to 400nm or less.

In one example, the electrochromic device of the present application may further include an ion storage layer between the electrolyte layer and the counter electrode layer. The ion storage layer may mean a layer formed to match charge balance with the electrochromic layer at the time of oxidation-reduction reaction for electrochromic.

The ion storage layer may comprise an electrochromic material having different coloration characteristics from those of the electrochromic material used in the electrochromic layer. For example, when the electrochromic layer comprises a reductive electrochromic material, the ion storage layer may comprise an oxidative electrochromic material. Furthermore, the opposite is possible.

In one example, the electrochromic device of the present application may further include a passivation layer. The passivation layer may prevent deterioration due to side reactions between electrolyte ions and metal components contained in the conductive layer.

In one example, the passivation layer may include a transparent conductive oxide. As the transparent conductive oxide, the above-mentioned materials can be used.

In one example, the passivation layer may be located on a side surface of the conductive layer, for example, between a light-transmitting substrate to be described below and the conductive layer, or may be located between the electrochromic layer and the conductive layer, or between the electrochromic layer and the electrolyte layer.

In one example, the electrochromic device may also include a light-transmissive substrate on the outermost side of the device. For example, the light-transmitting substrate may be located on a side surface of the conductive layer and/or the counter electrode layer. The transmittance of the light-transmitting substrate may be the same as that of the counter electrode layer described above.

In one example, the type of the light-transmitting substrate is not particularly limited, but for example, glass or a polymer resin may be used. More specifically, the following may be used as the light-transmitting substrate: polyester films such as PC (polycarbonate), PEN (poly (ethylene naphthalate)), or PET (poly (ethylene terephthalate)); acrylic films such as PMMA (poly (methyl methacrylate)); or polyolefin films, such as PE (polyethylene) or PP (polypropylene); and so on.

In another example, the electrochromic device may also include a power source. The manner of electrically connecting the power source to the device is not particularly limited, and this may be appropriately performed by those skilled in the art.

In one example of the present application, the present application relates to an apparatus, instrument or equipment comprising said device. The type of device or instrument is not particularly limited, but may be, for example, a computer or mobile phone case, wearable equipment such as a smart watch or smart garment, or building materials such as windows. The device may be used as a decorative film in such apparatus, instruments or equipment.

Advantageous effects

According to an example of the present application, an electrochromic device capable of realizing various aesthetic senses, color senses, or stereoscopic color patterns while having excellent durability, and an apparatus or instrument including the same may be provided.

Drawings

Fig. 1 is a graph recording the driving characteristics of the examples and comparative examples.

Detailed Description

Hereinafter, the present application will be described in detail by examples. However, the scope of protection of the present application is not limited by the embodiments to be described below.

Experimental example 1: determination of the color appearance of a conductive layer

Preparation example 1

Preparation of AlO with a thickness of 54.6nm by sputtering deposition_xN_yA laminate in which the layer was laminated with transparent PET. The specific resistance and the observed color of the laminate are shown in table 1.

Preparation examples 2 to 3

Laminates were prepared in the same manner except for changing AlO as shown in table 1 below_xN_yThe thickness of the layer.

[ Table 1]

Experimental example 2: confirmation of drive characteristics of device

The following methods or apparatus were used to measure values associated with this experiment.

< measurement of Charge >

The change in the amount of charge of each of the devices in examples and comparative examples was measured with a potentiostat device using a Potential Step Chronoamperometry (PSCA) while increasing the driving cycle.