阅读说明：本技术 一种彩色μLED发光显示器件 (Color mu LED light-emitting display device ) 是由 周雄图 王文雯 张永爱 郭太良 吴朝兴 林志贤 严群 于 2019-10-16 设计创作，主要内容包括：本发明涉及一种彩色μLED发光显示器件,其特征在于：包括从上到下依次设置的上驱动电极基板、上驱动电极,μLED晶粒、下驱动电极和下驱动电极基板；所述μLED晶粒由至少2种不同颜色的发光层堆叠而成,不同颜色发光层之间设置有载流子阻挡层；所述μLED晶粒均匀放置于上、下驱动电极之间；所述上下驱动电极均连接于交流控制模块,所述交流控制模块提供交变驱动信号,通过电磁耦合实现对μLED晶粒的点亮；且通过控制交变驱动信号的电压和频率大小来控制载流子在不同发光层进行复合,发出不同颜色光,实现彩色μLED发光显示。本发明实现非直接电学接触和电压调控颜色方法,可免去巨量转移和色彩转化工艺,有效地降低工艺成本。(The invention relates to a color mu LED light-emitting display device, which is characterized in that: the micro-LED driving circuit comprises an upper driving electrode substrate, an upper driving electrode, mu LED crystal grains, a lower driving electrode and a lower driving electrode substrate which are arranged from top to bottom in sequence; the mu LED crystal grain is formed by stacking at least 2 luminescent layers with different colors, and a carrier blocking layer is arranged between the luminescent layers with different colors; the mu LED crystal grains are uniformly arranged between the upper driving electrode and the lower driving electrode; the upper and lower driving electrodes are connected to an alternating current control module, the alternating current control module provides alternating driving signals, and mu LED crystal grains are lightened through electromagnetic coupling; and the voltage and the frequency of the alternating driving signal are controlled to control the current carriers to be compounded in different luminous layers to emit different colors of light, so that the luminous display of the color mu LED is realized. The invention realizes the indirect electrical contact and the voltage color control method, can avoid a huge amount of transfer and color conversion processes, and effectively reduces the process cost.)

1. a color μ LED light emitting display device, characterized by: the micro-LED driving circuit comprises an upper driving electrode substrate, an upper driving electrode, mu LED crystal grains, a lower driving electrode and a lower driving electrode substrate which are arranged from top to bottom in sequence; the mu LED crystal grain comprises at least 2 luminous layers with different colors, and a carrier blocking layer is arranged between the luminous layers with different colors; the mu LED crystal grains are uniformly arranged between the upper driving electrode and the lower driving electrode; the upper and lower driving electrodes are connected to an alternating current control module, the alternating current control module provides alternating driving signals, and mu LED crystal grains are lightened through electromagnetic coupling; and the voltage and the frequency of the alternating driving signal are controlled to control the current carriers to be compounded in different luminous layers to emit different colors of light, so that the luminous display of the color mu LED is realized.

2. The color μ LED light emitting display device according to claim 1, wherein the μ LED die further comprises a buffer layer, an n-type doped semiconductor layer, a light emitting layer, a carrier blocking layer and a p-type doped semiconductor layer, and the die size is 1nm ~ 1000 μm.

3. The color mu LED light-emitting display device according to claim 2, wherein the p-type semiconductor material has a thickness of 1nm to 2.0 μm, the light-emitting structure has a thickness of 1nm to 1.0 μm, the n-type semiconductor material has a thickness of 1nm to 2.5 μm, and the carrier blocking layer has a blocking effect on electrons or holes and has a thickness of 1nm ~ 100 nm.

4. A color μ LED light emitting display device according to claim 1, wherein: at least one of the upper driving electrode and the lower driving electrode is a transparent electrode, and a certain interval is formed between the two electrodes to form an independent space.

5. A color μ LED light emitting display device according to claim 1, further characterized by: and the insulating medium layer is arranged on the surfaces of the two driving electrodes or the outer surface of the mu LED crystal grain.

6. A color μ LED light emitting display device according to claim 1, further characterized by: the alternating current control module provides alternating voltage with amplitude and polarity changing along with time, the waveform of the alternating voltage comprises sine waves, triangular waves, square waves, pulses and composite waveforms thereof, the frequency of the alternating voltage is 1Hz-1000MHz, and the duty ratio is adjustable.

Technical Field

The invention relates to the field of integrated semiconductor display, in particular to a color mu LED light-emitting display device.

Background

The LED display has the advantages of self-luminescence, high brightness and luminous efficiency, low power consumption, high stability, etc., and is widely used in various occasions. With the reduction of the size of the LED chip and the pixel pitch, the LED display is expected to realize flexible, highly transparent, interactive, and modularly-tileable display, and is considered to be a revolutionary display technology with full functions and full application fields. The mu LED display is a novel display technology of an array formed by micron-scale LED luminous pixels, and the nLED (nanometer LED) display is a novel display technology of an array formed by nanometer-scale LED luminous pixels. At present, major LED chips, display panels and display application manufacturers at home and abroad have actively invested in the development of ultra-high density, small pitch LED (μ LED and nLED) displays. When the size of the LED chip is small to a certain extent, the handling of the chip becomes more and more difficult, especially for nLED dies, how to orderly transfer the dies with different light emitting colors onto the circuit substrate by various mechanical tools, and it becomes an important technical challenge to realize precise electrical contact between the μ LED die and the driving electrode by precise alignment and bonding. On the other hand, the traditional mu LED generally adopts a red, green and blue mu LED chip independent light emitting method and a color conversion method based on quantum dots or fluorescent powder, the process is complex, and when the mu LED chip is small to a certain extent, the independent light emitting material method and the color conversion method face huge technical challenges.

Disclosure of Invention

In view of the above, the present invention provides a color μ LED light emitting display device, in which a μ LED die includes light emitting layers emitting light of different colors, and a carrier blocking layer is disposed between the light emitting layers of different colors; the light emitting of different colors is realized by regulating and controlling the voltage, so that a huge amount of transfer and color conversion processes can be omitted, and the process cost is effectively reduced.

In order to achieve the purpose, the invention adopts the following technical scheme:

A color mu LED light-emitting display device comprises an upper driving electrode substrate, an upper driving electrode, mu LED crystal grains, a lower driving electrode and a lower driving electrode substrate which are arranged from top to bottom in sequence; the mu LED crystal grain comprises at least 2 luminous layers with different colors, and a carrier blocking layer is arranged between the luminous layers with different colors; the mu LED crystal grains are uniformly arranged between the upper driving electrode and the lower driving electrode; the upper and lower driving electrodes are connected to an alternating current control module, the alternating current control module provides alternating driving signals, and mu LED crystal grains are lightened through electromagnetic coupling; and the voltage and the frequency of the alternating driving signal are controlled to control the current carriers to be compounded in different luminous layers to emit different colors of light, so that the luminous display of the color mu LED is realized.

Further, the mu LED crystal grain also comprises a buffer layer, an n-type doped semiconductor layer, a light-emitting layer, a carrier blocking layer and a p-type doped semiconductor layer, and the crystal grain size is 1 nanometer ~ 1000 micrometers.

Furthermore, the thickness of the p-type semiconductor material is 1nm-2.0 μm, the thickness of the light-emitting structure is 1nm-1.0 μm, the thickness of the n-type semiconductor material is 1nm-2.5 μm, and the carrier blocking layer has a blocking effect on electrons or holes and is 1 nanometer ~ 100 nanometers.

Furthermore, at least one of the upper driving electrode and the lower driving electrode is a transparent electrode, and a certain interval is formed between the two electrodes to form an independent space.

Furthermore, an insulating medium layer is arranged on the surfaces of the two driving electrodes or the outer surface of the mu LED crystal grain.

Furthermore, the alternating current control module provides alternating voltage with amplitude and polarity changing along with time, the waveform of the alternating voltage comprises sine waves, triangular waves, square waves, pulses and composite waveforms thereof, the frequency of the alternating voltage is 1Hz-1000MHz, and the duty ratio is adjustable.

Compared with the prior art, the invention has the following beneficial effects:

The mu LED crystal grain comprises light emitting layers emitting light with different colors, and carrier blocking layers are arranged between the light emitting layers with different colors; the light emitting of different colors is realized by regulating and controlling the voltage, so that a huge amount of transfer and color conversion processes can be omitted, and the process cost is effectively reduced.

Drawings

Fig. 1 is a schematic diagram of a structure of a color LED light-emitting display device according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a mu LED die according to an embodiment of the invention.

In the figure: 01-upper driving electrode substrate, 02-lower driving electrode substrate, 03-upper driving electrode, 04-lower driving electrode, 05-mu LED crystal grain, 06-indirect electrical contact module, 051-buffer layer, 052-n type semiconductor layer, 053-luminous layer, 054-electronic barrier layer, 055-p type semiconductor layer, 056 insulating layer, 0531-carrier barrier layer 3, 0532-blue luminous layer, 0533-carrier barrier layer 2, 0534-green luminous layer, 0535-carrier barrier layer 1, 0536-red luminous layer.

Detailed Description

The invention is further explained below with reference to the drawings and the embodiments.

Referring to fig. 1, the present invention provides a color mu LED light emitting display device, which includes an upper driving electrode substrate, an upper driving electrode, a mu LED crystal grain, a lower driving electrode and a lower driving electrode substrate, which are sequentially arranged from top to bottom; the mu LED crystal grain comprises at least 2 luminous layers with different colors, and a carrier blocking layer is arranged between the luminous layers with different colors; the mu LED crystal grains are uniformly arranged between the upper driving electrode and the lower driving electrode; the upper and lower driving electrodes are connected to an alternating current control module, the alternating current control module provides alternating driving signals, and mu LED crystal grains are lightened through electromagnetic coupling; and the voltage of the alternating driving signal is controlled to control the current carriers to be compounded in different luminous layers to emit different colors of light, so that the color mu LED luminous display is realized.

In the embodiment, the mu LED crystal grain further comprises a buffer layer, an n-type doped semiconductor layer, a light emitting layer, a carrier blocking layer, a p-type doped semiconductor layer and an insulating layer, the size of the crystal grain is 1 nanometer ~ 1000 micrometers, the thickness of the p-type semiconductor material is 1nm-2.0 micrometers, the thickness of the light emitting structure is 1nm-1.0 micrometers, the thickness of the n-type semiconductor material is 1nm-2.5 micrometers, the carrier blocking layer has a blocking effect on electrons or holes, the thickness is 1 nanometer ~ 100 nanometers, and the size of corresponding voltage is adjusted by controlling the thickness and potential energy of the carrier blocking layer, so that most of electron hole recombination is limited in the light emitting layer with a certain color.

In this embodiment, at least one of the upper driving electrode and the lower driving electrode is a transparent electrode, and a certain space is formed between the two electrodes to form an independent space.

In this embodiment, the display device is further provided with an insulating medium layer disposed on the surfaces of the two driving electrodes or the outer surface of the μ LED die.

In this embodiment, the alternating current control module provides an alternating voltage whose amplitude and polarity change with time, the waveform of the alternating voltage includes a sine wave, a triangular wave, a square wave, a pulse and a composite waveform thereof, the frequency of the alternating voltage is 1Hz to 1000MHz, and the duty ratio is adjustable.

in this embodiment, as shown In fig. 2, preferably, the μ LED is a GaN-based LED formed by an epitaxial method, the p-doped GaN layer has a thickness of 200 nm, the blue light emitting layer is a [ In _0.2 Ga _0.8 N (3 nm)/GaN (10 nm) ] multiple quantum well, the green light emitting layer is a [ In _0.3 Ga _0.7 N (3 nm)/GaN (10 nm) ] multiple quantum well, the red light emitting layer is a [ In _0.4 Ga _0.6 N (3 nm)/GaN (10 nm) ] multiple quantum well, the N-doped GaN layer is Si-doped GaN having a thickness of 3 μm, the electron blocking layer is Mg-doped In _0.2 Ga _0.8 N, the carrier blocking layer is Al-doped GaN, specifically, the carrier blocking layer 1 is [ GaN (5 nm) Al _0.2 Ga _0.8 N (10 nm)/GaN (5 nm) ], the carrier blocking layer 2 is [ GaN (5 nm) Al _0.1 Ga _0.9 N (10 nm)/GaN (5 nm) ], the carrier blocking layer is GaN (5 nm), the carrier blocking layer 633 nm) is a thickness of [ GaN (5 nm) Al _0.1 Ga _0.95/GaN (_0.95) as a surface insulating silica layer with a thickness of 200 nm.

When the voltage is increased (such as U _G = 80V), holes can cross the carrier blocking layer 1 and the carrier blocking layer 2 and reach the blue light emitting layer, the excess holes are blocked by the carrier blocking layer 3, holes can be limited to the green light emitting layer and the electrons are recombined, and the device emits green light

Preferably, the driving electrodes are disposed on different substrates, and the substrate of the driving electrodes is Indium Tin Oxide (ITO) deposited on a glass substrate, and has a thickness of about 150 nm and a sheet resistance of about 20 Ω/sq.

Preferably, the waveform of the alternating voltage is sine wave with the frequency of 100 KHz, the driving electrode and the nano LED crystal grain are isolated by a dielectric layer, and the nano LED crystal grain is lightened by electrical coupling under the alternating driving signal.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.