CN111834390B - Full-color triode luminescent tube display device and manufacturing method - Google Patents

Abstract

The application relates to a full-color triode luminescent tube display device and a manufacturing method thereof. And applying a low-power variable input signal between the first contact electrode and the second contact electrode of the R unit, the G unit and the B unit respectively, and applying a forward bias voltage between the first contact electrode and the third contact electrode of the R unit, the G unit and the B unit respectively so that the R unit, the G unit and the B unit emit light. The application can realize that the light-emitting chip is driven by a low-power input signal to emit light to excite the color conversion layer, thereby realizing full-color display.

Description

A full-color triode light-emitting tube display device and its manufacturing method

Technical field

The present invention relates to the technical field of semiconductor display light-emitting device design, in particular to a full-color triode light-emitting tube display device and a manufacturing method.

Background technique

Light-emitting diodes (LEDs) are increasingly used in displays due to their long life, small size, low power consumption, high brightness, fast response and many other advantages. The micro-light-emitting diode (μLED) derived from it refers to the miniaturization of traditional LEDs to form micron-level pitch LED arrays to achieve ultra-high-density pixel resolution. It can be widely used in soft, transparent displays, AR, VR and other fields. It is the latest One of the most promising next-generation display devices. Compared with OLED and LCD displays, μLED display colors are easier to adjust accurately, have long luminous life and high brightness. It is the only high luminous efficiency and low power consumption device that can integrate driving, lighting, and signal transmission, and realizes ultra-large-scale integrated luminescence. display device of the unit.

Despite its many advantages, for LED or μLED displays, full-color issues are one of the key technologies that must be solved for their display applications. Full-color solutions are divided into two categories, one is the RGB three-color chip that directly emits light, and the other is the monochrome chip combined with the color conversion layer. Although the former technology is relatively mature at present, it is still difficult to grow RGB three-color chips with different wavelengths on the same substrate. Moreover, the three colors must be driven separately, and the driving circuit is complex and costly. Therefore, full-color technology is now more promising. Technology is definitely the latter. This technology places a three-primary color fluorescence conversion layer on a single short-wavelength μLED array, thereby converting the light emitted by the chip into RGB three colors to achieve full-color display. At present, the main methods for realizing μLED full-color display include the color conversion method of blue μLED + red and green quantum dots, nano-column RGB pixel light source, optical prism synthesis method and Chromover wavelength conversion technology. Among them, the color conversion of blue μLED + red and green quantum dots is currently the mainstream technical route to achieve full-color μLED display. However, whether the LEDs on the market today are vertical structures or flip-chip structures, they are basically driven by two electrodes, that is, there are only two contact electrodes acting on both ends of the LED. Although this driving method is relatively common, the low-power signal output by the control chip often cannot directly drive the LED, and power amplification is required in the middle. These power amplifier circuits will significantly increase the design complexity of the drive circuit. Especially for μLEDs, complex driving circuits are not conducive to the construction of highly integrated systems.

Contents of the invention

In view of this, the purpose of the present invention is to propose a full-color triode light-emitting tube display device and a manufacturing method, which can use a low-power input signal to drive the light-emitting chip to emit light and excite the color conversion layer, thereby realizing full-color display.

The present invention adopts the following solution: a full-color triode light-emitting tube display device, including a buffer layer, a first semiconductor layer provided on the buffer layer, and a first contact electrode provided on the first semiconductor layer. R unit to display red light, G unit to display green light, and B unit to display blue light;

The R unit, G unit and B unit all include a second semiconductor layer, a third semiconductor layer, a blue light emitting layer, a fourth semiconductor layer and a third contact electrode from bottom to top; wherein the R unit, G unit and B unit all include It also includes a second contact electrode disposed on the second semiconductor layer; wherein the R unit also includes a red color conversion layer and a distributed Bragg reflection layer DBR1 disposed on the third contact electrode in this unit in sequence, and the G unit also includes The green light color conversion layer and the distributed Bragg reflective layer DBR2 are sequentially provided on the third contact electrode in this unit. Unit B also includes a distributed Bragg reflection layer DBR3 provided on the third contact electrode in this unit;

Wherein, a variable input signal is applied between the first contact electrode and the second contact electrode in the R unit, G unit and B unit respectively, and between the first contact electrode and the R unit, G unit and B unit A forward bias voltage is applied between the third contact electrodes, causing the R unit, G unit and B unit to emit light.

Among them, the first semiconductor layer, the second semiconductor layer, the third semiconductor layer, the first contact electrode, the second contact electrode (SCE1) in the R unit, the second contact electrode (SCE2) in the G unit, and the second contact electrode (SCE2) in the B unit. The second contact electrode (SCE3) constitutes a triode structure; the third semiconductor layer, the blue light emitting layer, the fourth semiconductor layer and the third contact electrode constitute the light emitting chip structure; the red light color conversion layer and the distributed Bragg reflection layer in the R unit ( DBR1), the green color conversion layer and the distributed Bragg reflection layer (DBR2) in the G unit, and the distributed Bragg reflection layer (DBR3) in the B unit constitute the color conversion structure.

The triode structure amplifies the power of the input signal, enabling the low-power input signal to drive the light-emitting chip to emit light, thereby stimulating the light conversion layer and achieving full-color display; at the same time, the triode can also effectively reduce the driving circuit of the light-emitting device. Design complexity and improve the integration of display devices. Wherein, the third semiconductor layer is the collector of the triode structure and also the cathode or anode of the light-emitting chip.

Further, the first semiconductor layer is an N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, and the fourth semiconductor layer is a P-type semiconductor layer; or the first semiconductor layer is an N-type semiconductor layer. The semiconductor layer is a P-type semiconductor layer, the second semiconductor layer is an N-type semiconductor layer, the third semiconductor layer is a P-type semiconductor layer, and the fourth semiconductor layer is an N-type semiconductor layer.

Further, when the first semiconductor layer is an N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, and the fourth semiconductor layer is a P-type semiconductor layer, the The voltage signal between the electrode and the second contact electrode in unit R, unit G and unit B is positive polarity, that is, the second contact electrode SCE1 in unit R, the second contact electrode SCE2 in unit G and the second contact electrode SCE2 in unit B are positive. The potential of the second contact electrode SCE3 is higher than the potential of the first contact electrode, and the voltage signal applied between the first contact electrode and the third contact electrode in the R unit, G unit and B unit is of positive polarity, that is, in the R unit The potential of the third contact electrode TCE1, the third contact electrode TCE2 in the G unit and the third contact electrode TCE3 in the B unit is higher than the potential of the first contact electrode.

Further, when the first semiconductor layer is a P-type semiconductor layer, the second semiconductor layer is an N-type semiconductor layer, the third semiconductor layer is a P-type semiconductor layer, and the fourth semiconductor layer is an N-type semiconductor layer, the The voltage signal between the electrode and the second contact electrode in the R unit, G unit, and B unit is negative polarity, that is, the second contact electrode SCE1 in the R unit, the second contact electrode SCE2 in the G unit, and the second contact electrode SCE2 in the B unit The potential of the second contact electrode SCE3 is lower than the potential of the first contact electrode, and the voltage model applied between the first contact electrode and the third contact electrode in the R unit, G unit and B unit is negative polarity, that is, in the R unit The potential of the third contact electrode TCE1, the third contact electrode TCE2 in the G unit and the third contact electrode TCE3 in the B unit is lower than the potential of the first contact electrode.

Further, the first semiconductor layer is a semiconductor layer with a heavily doped concentration, which is 1 to 5 orders of magnitude higher than the doping concentration of the second semiconductor layer.

Further, the voltage amplitude applied between the first contact electrode and the second contact electrode in the R unit, G unit, and B unit is smaller than the voltage amplitude applied between the first contact electrode and the third contact in the R unit, G unit, and B unit. voltage amplitude between electrodes.

Further, the distributed Bragg reflection layers provided in the R unit, G unit and B unit are all stacked by two types of films with high refractive index and low refractive index. The thickness of each layer of film is: Determine, where n is the refractive index of the film, d is the film thickness, θ is the light incident angle, λ is the central wavelength, q is a constant, q≥0, and when q is a positive odd number, the reflectivity has an extreme value; set three The number of film stack layers of the distributed Bragg reflective layer are x, y, and z respectively, then all three are N or N+0.5, and N is a positive integer.

Further, the distributed Bragg reflection layer DBR1 in the R unit is used for total reflection of blue light and high transmission red light, and the distributed Bragg reflection layer DBR2 in the G unit is used for total reflection of blue light and high transmission green light, so The distributed Bragg reflective layer DBR3 in unit B is used to reflect part of the blue light and adjust the light intensity, thereby regulating the light output ratio of the RGB three-color light to better achieve full-color display.

Further, the buffer layer, the first semiconductor layer, the second semiconductor layer, the third semiconductor layer, the blue light emitting layer, and the fourth semiconductor layer are single-layer semiconductor structures with the same doping concentration, or have gradient or gradual changes. Doped multilayer semiconductor structure.

The invention also provides a method for manufacturing a full-color triode light-emitting tube display device, which includes the following steps:

sequentially growing a buffer layer, a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, a blue light emitting layer and a fourth semiconductor layer on the substrate;

Etch the above layer to expose part of the second semiconductor layer to form an array module, and divide it into R units, G units and B units;

Continue etching on the exposed second semiconductor layer until the first semiconductor layer is exposed;

Grow a first contact electrode on the exposed first semiconductor layer (far right); and grow a second contact electrode on the exposed second semiconductor layer in the R unit, G unit, and B unit respectively;

A third contact electrode is grown on the surface of the fourth semiconductor layer in the R unit, G unit, and B unit respectively;

A red light color conversion layer and a green light color conversion layer are respectively prepared on the third contact electrode surfaces of the R unit and the G unit (by deposition), and the lengths of the two are respectively shorter than the third contact electrodes TCE1 and TCE2;

A distributed Bragg reflection layer is deposited on the red light color conversion layer, the green light color conversion layer of the R unit and the G unit, and the third contact electrode surface of the B unit respectively. The length of the distributed Bragg reflective layer DBR3 in unit B is shorter than the third contact electrode TCE3. By adjusting the thickness of the high and low refractive index films of the distributed Bragg reflective layer and the number of alternately stacked film layers, the wavelength of the emitted light and the intensity of the reflected light are controlled. Wavelength and the ratio of transmission and reflection. DBR1 is used for total reflection blue light and high transmission red light, DBR2 is used for total reflection blue light and high transmission green light, and DBR3 is used to reflect part of the blue light and adjust the light intensity, thereby regulating the light output ratio of RGB three-color light to better achieve full color. show.

Preferably, the thickness of the second semiconductor layer is 0.5 nm to 2 μm. The host material of the second semiconductor layer may be, but is not limited to, GaAs, GaP, GaN, ZnSe, SiC, Si, ZnSe, graphene, black phosphorus, MoS ₂ , CNT, or may be, but is not limited to, CuPc, Alq3 and other organic materials. Semiconductor material.

Preferably, the thickness of the first semiconductor layer is 0.5 μm to 5 μm, the thickness of the third semiconductor layer is 0.5 μm to 5 μm, and the thickness of the fourth semiconductor layer is 10 nm to 2 μm. The host materials of the first semiconductor layer, the third semiconductor layer, and the fourth semiconductor layer may be, but are not limited to, inorganic semiconductor materials such as GaAs, GaP, GaN, ZnSe, SiC, Si, ZnSe, etc., and may also be, but are not limited to, CuPc, Alq3 and other organic semiconductor materials.

Wherein, the first contact electrode forms an ohmic contact with the first semiconductor layer; the second contact electrode (SCE1 in the R unit, SCE2 in the G unit and SCE3 in the B unit) and the second semiconductor layer The third contact electrode (TCE1 in the R unit, TCE2 in the G unit, and TCE3 in the B unit) respectively forms an ohmic contact with the fourth semiconductor layer, and the third contact electrode is Transparent electrode.

Preferably, the blue light-emitting layer includes a multi-quantum well active layer and a hole blocking layer or electron blocking layer to improve carrier recombination efficiency; it can also be, but is not limited to, an organic film with a light-emitting function and a A functional layer for improving carrier recombination efficiency; it may also be, but is not limited to, a nanomaterial film with a light-emitting function and a functional layer for improving carrier recombination efficiency.

Preferably, the red light in the R unit is obtained by exciting the red light conversion layer from the blue light emitting layer; the red light conversion layer can be a red quantum dot material or phosphor or a combination of both and other polymers. hybrid. The green light in the G unit is obtained by exciting the green light conversion layer from the blue light emitting layer; the green light conversion layer may be a green quantum dot material or a phosphor or a combination of the two and other polymers.

Preferably, the substrate can be, but is not limited to, sapphire, GaAs, GaP, GaN, ZnSe, SiC, Si, ZnSe; the substrate can remain on the device, or can be used during the manufacturing process of the wavelength-converted triode light-emitting device. Remove.

Preferably, the buffer layer, the first semiconductor layer, the second semiconductor layer, the third semiconductor layer, the light-emitting layer and the fourth semiconductor layer can be formed by, but are not limited to, epitaxy, deposition, coating, assembly, transfer, and lamination. .

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

(1) Compared with ordinary color LEDs, the full-color triode light-emitting tube display device proposed by the present invention integrates the peripheral amplification driving circuit into the light-emitting chip, and has an extra driving electrode as a control terminal to amplify the power of the input signal. , realizing driving the light-emitting chip with a low-power input signal, effectively reducing the complexity of the drive circuit design of the LED display device, especially the μLED display device, and improving the integration of the LED display device.

(2) The present invention can use the blue light-emitting chip to excite the red and green light conversion layers in the R unit and G unit to emit red/green light to achieve full-color display. At the same time, the DBR layer on the light conversion layer is used to effectively fully reflect the light excited by the light-emitting chip and the light generated by the high-transmission light conversion layer to improve the device conversion efficiency.

(3) The manufacturing method proposed by the present invention is simple and low-cost, and can quickly and effectively prepare R, G, and B color modules on the same substrate, thereby achieving full-color display; and has good color rendering, color purity and conversion efficiency. High, which is conducive to promoting the industrialization efficiency and market competitiveness of μLED display.

Description of the drawings

Figure 1 is a schematic cross-sectional view of a full-color triode light-emitting tube display device according to an embodiment of the present invention.

FIG. 2 is a schematic three-dimensional view of a full-color triode light-emitting tube display device according to an embodiment of the present invention.

Figure 3 is a flow chart of the preparation of a full-color triode light-emitting tube display device according to an embodiment of the present invention.

Figure 4 is a schematic diagram of the preparation process of a full-color triode light-emitting tube display device according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a driving method of a full-color triode LED display device according to an embodiment of the present invention.

FIG. 6 is a driving equivalent circuit of a full-color triode light-emitting tube display device according to an embodiment of the present invention.

In the figure, 1 is a sapphire substrate, 2 is a buffer layer, 6 is an R unit, 7 is a G unit, 8 is a B unit, 301 is the first semiconductor layer, 302 is the second semiconductor layer, and 303 is the third semiconductor layer. 304 is the light-emitting layer, 305 is the fourth semiconductor layer, 401 is the first contact electrode, 501, 502 and 503 are the second contact electrodes SCE1, SCE2 and SCE3 respectively, 601, 602 and 603 are the third contact electrodes TCE1 and TCE2 respectively. and TCE3, 701 is the red light conversion layer, 702 is the green light conversion layer, 801, 802 and 803 are DBR1, DBR2 and DBR3 respectively.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and examples.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meanings commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular forms are also intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, it will be understood that when the terms "comprises" and/or "includes" are used in this specification, they indicate There are features, steps, operations, means, components and/or combinations thereof.

As shown in Figures 1 and 2, this embodiment provides a full-color triode light-emitting tube display device, including a buffer layer 2, a first semiconductor layer 301 provided on the buffer layer, and a first semiconductor layer 301 provided on the buffer layer. The first contact electrode 401, the R unit 6 for displaying red light, the G unit 7 for displaying green light, and the B unit 8 for displaying blue light;

The R unit, G unit and B unit all include a second semiconductor layer 302, a third semiconductor layer 303, a blue light emitting layer 304, a fourth semiconductor layer 305 and a third contact electrode 601 from bottom to top; wherein the R unit, G unit Both the unit and the B unit also include a second contact electrode 501/502/503 disposed on the second semiconductor layer; the R unit also includes a red color conversion layer 701 and a red color conversion layer 701 disposed on the third contact electrode in this unit. Distributed Bragg reflective layer DBR1 (801). Unit G also includes a green color conversion layer 802 and distributed Bragg reflective layer DBR2 (802) arranged on the third contact electrode in this unit. Unit B also includes a green light color conversion layer 802 and a distributed Bragg reflective layer DBR2 (802) arranged on the third contact electrode in this unit. Distributed Bragg reflective layer DBR3 (803) on the third contact electrode in the unit;

Wherein, a variable input signal is applied between the first contact electrode and the second contact electrode in the R unit, G unit and B unit respectively, and between the first contact electrode and the R unit, G unit and B unit A forward bias voltage is applied between the third contact electrodes, causing the R unit, G unit and B unit to emit light.

Among them, the first semiconductor layer, the second semiconductor layer, the third semiconductor layer, the first contact electrode, the second contact electrode (SCE1) in the R unit, the second contact electrode (SCE2) in the G unit, and the second contact electrode (SCE2) in the B unit. The second contact electrode (SCE3) constitutes a triode structure; the third semiconductor layer, the blue light emitting layer, the fourth semiconductor layer and the third contact electrode constitute the light emitting chip structure; the red light color conversion layer and the distributed Bragg reflection layer in the R unit ( DBR1), the green color conversion layer and the distributed Bragg reflection layer (DBR2) in the G unit, and the distributed Bragg reflection layer (DBR3) in the B unit constitute the color conversion structure.

The triode structure amplifies the power of the input signal, enabling the low-power input signal to drive the light-emitting chip to emit light, thereby stimulating the light conversion layer and achieving full-color display; at the same time, the triode can also effectively reduce the driving circuit of the light-emitting device. Design complexity and improve the integration of display devices. Wherein, the third semiconductor layer is the collector of the triode structure and also the cathode or anode of the light-emitting chip.

In this embodiment, the first semiconductor layer is an N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, and the fourth semiconductor layer is a P-type semiconductor layer; or The first semiconductor layer is a P-type semiconductor layer, the second semiconductor layer is an N-type semiconductor layer, the third semiconductor layer is a P-type semiconductor layer, and the fourth semiconductor layer is an N-type semiconductor layer.

In this embodiment, when the first semiconductor layer is an N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, and the fourth semiconductor layer is a P-type semiconductor layer, The voltage signal between the first contact electrode and the second contact electrode in the R unit, G unit and B unit is positive polarity, that is, the second contact electrode SCE1 in the R unit, the second contact electrode SCE2 and B in the G unit The potential of the second contact electrode SCE3 in the unit is higher than the potential of the first contact electrode, and the voltage signal applied between the first contact electrode and the third contact electrode in the R unit, G unit and B unit is of positive polarity, that is, The potential of the third contact electrode TCE1 in the R unit, the third contact electrode TCE2 in the G unit, and the third contact electrode TCE3 in the B unit is higher than the potential of the first contact electrode.

In this embodiment, when the first semiconductor layer is a P-type semiconductor layer, the second semiconductor layer is an N-type semiconductor layer, the third semiconductor layer is a P-type semiconductor layer, and the fourth semiconductor layer is an N-type semiconductor layer, The voltage signal between the first contact electrode and the second contact electrode in the R unit, G unit and B unit is negative polarity, that is, the second contact electrode SCE1 in the R unit, the second contact electrode SCE2 and B in the G unit The potential of the second contact electrode SCE3 in the unit is lower than the potential of the first contact electrode, and the voltage model applied between the first contact electrode and the third contact electrode in the R unit, G unit and B unit is negative polarity, that is, The potential of the third contact electrode TCE1 in the R cell, the third contact electrode TCE2 in the G cell, and the third contact electrode TCE3 in the B cell is lower than the potential of the first contact electrode.

In this embodiment, the first semiconductor layer is a semiconductor layer with a heavily doped concentration, which is 1 to 5 orders of magnitude higher than the doping concentration of the second semiconductor layer.

In this embodiment, the voltage amplitude applied between the first contact electrode and the second contact electrode in the R unit, G unit, and B unit is smaller than the voltage amplitude applied between the first contact electrode and the R unit, the G unit, and the B unit. The voltage amplitude between the third contact electrodes.

In this embodiment, the distributed Bragg reflection layers provided in the R unit, the G unit and the B unit are stacked by two types of films with high refractive index and low refractive index. The thickness of each layer of film is: Determine, where n is the refractive index of the film, d is the film thickness, θ is the light incident angle, λ is the central wavelength, q is a constant, q≥0, and when q is a positive odd number, the reflectivity has an extreme value; set three The number of film stack layers of the distributed Bragg reflective layer are x, y, and z respectively, then all three are N or N+0.5, and N is a positive integer.

In this embodiment, the distributed Bragg reflection layer DBR1 in the R unit is used for total reflection of blue light and high transmission red light, and the distributed Bragg reflection layer DBR2 in the G unit is used for total reflection of blue light and high transmission of green light. Light, the distributed Bragg reflective layer DBR3 in the B unit is used to reflect part of the blue light and adjust the light intensity, thereby regulating the light output ratio of the RGB three-color light to better achieve full-color display.

In this embodiment, the buffer layer, the first semiconductor layer, the second semiconductor layer, the third semiconductor layer, the blue light emitting layer, and the fourth semiconductor layer are single-layer semiconductor structures with the same doping concentration, or have gradient Or a multilayer semiconductor structure with gradually varying doping concentration.

As shown in Figure 3, this embodiment also provides a method for manufacturing a full-color triode light-emitting tube display device, which includes the following steps:

sequentially growing a buffer layer, a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, a blue light emitting layer and a fourth semiconductor layer on the substrate;

Etch the above layer to expose part of the second semiconductor layer to form an array module, and divide it into R units, G units and B units;

Continue etching on the exposed second semiconductor layer until the first semiconductor layer is exposed;

Grow a first contact electrode on the exposed first semiconductor layer (far right); and grow a second contact electrode on the exposed second semiconductor layer in the R unit, G unit, and B unit respectively;

A third contact electrode is grown on the surface of the fourth semiconductor layer in the R unit, G unit, and B unit respectively;

A red light color conversion layer and a green light color conversion layer are respectively prepared on the third contact electrode surfaces of the R unit and the G unit (by deposition), and the lengths of the two are respectively shorter than the third contact electrodes TCE1 and TCE2;

A distributed Bragg reflection layer is deposited on the red light color conversion layer, the green light color conversion layer of the R unit and the G unit, and the third contact electrode surface of the B unit respectively. The length of the distributed Bragg reflective layer DBR3 in unit B is shorter than the third contact electrode TCE3. By adjusting the thickness of the high and low refractive index films of the distributed Bragg reflective layer and the number of alternately stacked film layers, the wavelength of the emitted light and the intensity of the reflected light are controlled. Wavelength and the ratio of transmission and reflection. DBR1 is used for total reflection blue light and high transmission red light, DBR2 is used for total reflection blue light and high transmission green light, and DBR3 is used to reflect part of the blue light and adjust the light intensity, thereby regulating the light output ratio of RGB three-color light to better achieve full color. show.

Preferably, the thickness of the second semiconductor layer is 0.5 nm to 2 μm. The host material of the second semiconductor layer may be, but is not limited to, GaAs, GaP, GaN, ZnSe, SiC, Si, ZnSe, graphene, black phosphorus, MoS ₂ , CNT, or may be, but is not limited to, CuPc, Alq3 and other organic materials. Semiconductor material.

Preferably, the thickness of the first semiconductor layer is 0.5 μm to 5 μm, the thickness of the third semiconductor layer is 0.5 μm to 5 μm, and the thickness of the fourth semiconductor layer is 10 nm to 2 μm. The host materials of the first semiconductor layer, the third semiconductor layer, and the fourth semiconductor layer may be, but are not limited to, inorganic semiconductor materials such as GaAs, GaP, GaN, ZnSe, SiC, Si, ZnSe, etc., and may also be, but are not limited to, CuPc, Alq3 and other organic semiconductor materials.

Wherein, the first contact electrode forms an ohmic contact with the first semiconductor layer; the second contact electrode (SCE1 in the R unit, SCE2 in the G unit and SCE3 in the B unit) and the second semiconductor layer The third contact electrode (TCE1 in the R unit, TCE2 in the G unit, and TCE3 in the B unit) respectively forms an ohmic contact with the fourth semiconductor layer, and the third contact electrode is Transparent electrode.

Preferably, the blue light-emitting layer includes a multi-quantum well active layer and a hole blocking layer or electron blocking layer to improve carrier recombination efficiency; it can also be, but is not limited to, an organic film with a light-emitting function and a A functional layer for improving carrier recombination efficiency; it may also be, but is not limited to, a nanomaterial film with a light-emitting function and a functional layer for improving carrier recombination efficiency.

Preferably, the red light in the R unit is obtained by exciting the red light conversion layer from the blue light emitting layer; the red light conversion layer can be a red quantum dot material or phosphor or a combination of both and other polymers. hybrid. The green light in the G unit is obtained by exciting the green light conversion layer from the blue light emitting layer; the green light conversion layer may be a green quantum dot material or a phosphor or a combination of the two and other polymers.

Preferably, the buffer layer, the first semiconductor layer, the second semiconductor layer, the third semiconductor layer, the light-emitting layer and the fourth semiconductor layer can be formed by, but are not limited to, epitaxy, deposition, coating, assembly, transfer, and lamination. .

Preferably, the substrate can be, but is not limited to, sapphire, GaAs, GaP, GaN, ZnSe, SiC, Si, ZnSe; the substrate can remain on the device, or can be used during the manufacturing process of the wavelength-converted triode light-emitting device. Remove.

Next, this embodiment will be described in more detail with reference to FIGS. 1 to 5 .

Referring to Figure 1, a full-color triode light-emitting tube display device includes a substrate 1 (removable), a buffer layer 2 arranged on the surface of the substrate, a triode structure arranged on the buffer layer, a light-emitting chip structure and a color conversion Structure; the transistor structure, the light-emitting chip structure and the color conversion structure are arranged from bottom to top along the buffer layer, and the R unit 6 for displaying red light, and the R unit for displaying red light are sequentially formed along the lateral direction of the substrate 1. G unit 7 for displaying green light and B unit 8 for displaying blue light. Wherein, the triode structure includes a first semiconductor layer 301, a second semiconductor layer 302, a third semiconductor layer 303 from bottom to top, as well as a first contact electrode 401 drawn from the first semiconductor layer, a first contact electrode 401 drawn from the second semiconductor layer R unit 6 The second contact electrode (SCE1) 501 drawn from the inside, the second contact electrode (SCE2) 502 drawn from the G unit 7 and the second contact electrode (SCE3) 503 drawn from the B unit 8; the light-emitting chip structure is from bottom to top. It includes a third semiconductor layer 303, a blue light-emitting layer 304, a fourth semiconductor layer 304, and a third contact electrode (TCE1) 601 drawn from the fourth semiconductor layer R unit 6 and a third contact electrode drawn from the G unit 7. (TCE2) 602 and the third contact electrode (TCE3) 603 derived from the B unit 8. The color conversion structure includes the conversion layer 701 for displaying red light and the distributed Bragg reflection layer (DBR1) 801 in the R unit 6, The conversion layer 702 and the distributed Bragg reflection layer (DBR2) 802 in the G unit 7 are used to display green light, and the distributed Bragg reflection layer (DBR3) 803 in the B unit 8 is used to partially reflect blue light.

Among them, the substrate 1 of this embodiment adopts a sapphire substrate and is an a-plane, the material used for the buffer layer 2 is AlN, the first semiconductor layer 301 is an N-GaN layer, and the second semiconductor layer 302 is a P-GaN layer. The third semiconductor layer 303 is an N-GaN layer, and the light-emitting layer 304 is a hole blocking layer or electron blocking layer composed of three periods of In _a Ga _1-a N quantum well active layer and Al _b Ga _1-b N The fourth semiconductor layer 305 is P-GaN. The first contact electrode 401 is a gold copper electrode, the second contact electrodes SCE1501, SCE2502 and SCE3503 are all gold copper electrodes, and the transparent third contact electrodes TCE1601, TCE2602 and TCE3603 are all indium tin oxide (ITO). The red light conversion layer 701 uses a red quantum dot film, and the green light conversion layer 702 uses a green quantum dot film. Distributed Bragg reflector layers DBR1, DBR2 and DBR3 are all made of TiO ₂ and Al ₂ O ₃ films alternately stacked.

Specifically, in this embodiment, the first semiconductor layer and the third semiconductor layer are Mg-doped N-GaN, and the second and fourth semiconductor layers are Si-doped P-GaN. Further, in this embodiment, the Mg doping concentration of the first semiconductor layer is 1×10 ²¹ cm ^-3 , the Si doping concentration of the second semiconductor layer is 5×10 ¹⁸ cm ^-3 , and the Mg doping concentration of the third semiconductor layer The concentration is 1×10 ¹⁹ cm ^-3 , and the Si doping concentration of the fourth semiconductor layer is 5×10 ¹⁸ cm ^-3 .

The preparation method of the device in this embodiment is specifically implemented according to the following steps:

S11: Provide a sapphire substrate 1, place the sapphire substrate 1 in the MOCVD reaction chamber, set the temperature to 800°C to 1200°C, introduce trimethylaluminum and ammonia gas, and use hydrogen as a carrier to place the sapphire substrate 1 On the upper growth buffer layer 2, the first semiconductor layer N-GaN layer 301, the second semiconductor layer P-GaN layer 302, the third semiconductor layer N-GaN layer 303, the multi-quantum well light-emitting layer 304 and the fourth semiconductor layer P-GaN Layer 305, their thicknesses are respectively 1000nm, 2μm, 0.5μm, 3μm, 200nm and 1μm;

S12: Use ICP to etch the above layer to expose part of the second semiconductor layer 302 to form an array module;

S13: Continue etching on the second semiconductor layer 302 until the first semiconductor layer 301 is exposed;

S14: Grow the first contact electrode 401 on the rightmost side of the first semiconductor layer 301, and grow the second contact electrodes SCE1501, SCE2502 and SCE3503 on the exposed second semiconductor layer 302 in the R, G, and B units respectively;

S15: Grow third contact electrodes TCE1601, TCE2602 and TCE3603 respectively on the surface of the fourth semiconductor layer 305 in the R, G and B units;

S16: Prepare the red conversion layer 701 and the green conversion layer 702 by deposition on the surfaces of the third contact electrodes TCE1601 and TCE2602 of the R and G units respectively, and the lengths of the two are smaller than TCE1 and TCE2 respectively;

S17: Deposit DBR1, DBR2 and DBR3 on the surfaces of the red conversion layer 701, the green conversion layer 702 and the third contact electrode TCE3603 of the R, G and B units. The length of DBR3 is smaller than TCE3. By adjusting the high and low refraction of the distributed Bragg reflection layer The thickness of the rate film and the number of alternately stacked film layers are used to control the wavelength of the emitted light, the wavelength of the reflected light and the ratio of transmission and reflection. The DBR1 can reflect all blue light and transmit as much red light as possible; the DBR2 can reflect all blue light and transmit as much green light as possible; the DBR3 can reflect part of the blue light and adjust the intensity of the outgoing light, thereby regulating R and G , B three-color light emission ratio to better achieve full-color display. Among them, the thickness of TiO ₂ is 45nm, the thickness of Al ₂ O ₃ is 67nm, DBR1 contains 13 layers of stacked films, DBR2 contains 11 layers of stacked films, and DBR3 contains 5 layers of stacked films, and the top and bottom ends of all stacked films are is TiO ₂ .

Figure 5 is a schematic diagram of the driving method of the R, G, and B units of the full-color triode control type light-emitting device. The three units share the first contact electrode and the driving method is the same, except that the R and G units have additional color conversion layer modules. The blue light is converted into the required red light and green light respectively, thereby achieving full-color display. Therefore, here we only take unit B as an example to explain the driving method in detail, and the other two units will not be described again. As shown in Figure 5, a small-power variable input signal V ₁ is applied between the first contact electrode and the second contact electrode SCE3, and at the same time, a positive voltage is applied between the first contact electrode and the transparent third contact electrode TCE3. The bias voltage V ₂ can cause the blue light-emitting transistor chip to emit light, achieve power amplification of the input signal, and drive the LED with a low-power input signal. See Figure 6 for its equivalent circuit. The NPN transistor is connected to the common emitter of the LED. The base and emitter form an input loop, that is, a small power variable input signal V ₁ is applied between the first contact electrode and the second contact electrode SCE3. The collector and the emitter form an output loop, that is, a forward bias voltage V ₂ is applied between the first contact electrode and the third contact electrode TCE3, so that the triode can drive the LED to emit light.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any skilled person familiar with the art may make changes or modifications to equivalent changes using the technical contents disclosed above. Example. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (9)

1. A full-color triode light-emitting tube display device, characterized in that it includes a buffer layer, a first semiconductor layer provided on the buffer layer, and a first contact electrode provided on the first semiconductor layer, for display R unit for red light, G unit for displaying green light, and B unit for displaying blue light; The R unit, G unit and B unit all include a second semiconductor layer, a third semiconductor layer, a blue light emitting layer, a fourth semiconductor layer and a third contact electrode from bottom to top; wherein the R unit, G unit and B unit all include It also includes a second contact electrode disposed on the second semiconductor layer; wherein the R unit also includes a red color conversion layer and a distributed Bragg reflection layer DBR1 disposed on the third contact electrode in this unit in sequence, and the G unit also includes The green light color conversion layer and the distributed Bragg reflective layer DBR2 are sequentially provided on the third contact electrode in this unit. Unit B also includes a distributed Bragg reflection layer DBR3 provided on the third contact electrode in this unit; Wherein, a variable input signal is applied between the first contact electrode and the second contact electrode in the R unit, G unit and B unit respectively, and between the first contact electrode and the R unit, G unit and B unit A forward bias voltage is applied between the third contact electrodes, causing the R unit, G unit and B unit to emit light; The distributed Bragg reflection layer DBR1 in the R unit is used for total reflection of blue light and high transmission red light. The distributed Bragg reflection layer DBR2 in the G unit is used for total reflection of blue light and high transmission green light. The B unit The distributed Bragg reflective layer DBR3 in the display is used to reflect part of the blue light and adjust the light intensity, thereby regulating the light output ratio of the RGB three-color light to better achieve full-color display. 2. A full-color triode light-emitting tube display device according to claim 1, characterized in that the first semiconductor layer is an N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, and the third semiconductor layer The first semiconductor layer is an N-type semiconductor layer, and the fourth semiconductor layer is a P-type semiconductor layer; or the first semiconductor layer is a P-type semiconductor layer, the second semiconductor layer is an N-type semiconductor layer, and the third semiconductor layer is a P-type semiconductor layer, The fourth semiconductor layer is an N-type semiconductor layer. 3. A full-color triode light-emitting tube display device according to claim 2, characterized in that when the first semiconductor layer is an N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, and the third semiconductor layer When the fourth semiconductor layer is an N-type semiconductor layer and the fourth semiconductor layer is a P-type semiconductor layer, the voltage signal applied between the first contact electrode and the second contact electrode in the R unit, G unit, and B unit is of positive polarity, and the voltage signal applied between the first contact electrode and the second contact electrode in the R unit, G unit, and B unit is positive. The voltage signal between one contact electrode and the third contact electrode in the R unit, the G unit and the B unit is of positive polarity. 4. A full-color triode light-emitting tube display device according to claim 2, characterized in that when the first semiconductor layer is a P-type semiconductor layer, the second semiconductor layer is an N-type semiconductor layer, and the third semiconductor layer When the fourth semiconductor layer is a P-type semiconductor layer and the fourth semiconductor layer is an N-type semiconductor layer, the voltage signal applied between the first contact electrode and the second contact electrode in the R unit, G unit, and B unit has a negative polarity, and the voltage signal applied between the first contact electrode and the second contact electrode in the R unit, G unit, and B unit has a negative polarity. The voltage pattern between the first contact electrode and the third contact electrode in the R unit, G unit and B unit is negative polarity. 5. A full-color triode light-emitting tube display device according to claim 1, characterized in that the first semiconductor layer is a semiconductor layer with a heavily doped concentration, which is higher than the doping concentration of the second semiconductor layer. Concentrations are 1 to 5 orders of magnitude higher. 6. A full-color triode light-emitting tube display device according to claim 1, characterized in that the voltage amplitude applied between the first contact electrode and the second contact electrode in the R unit, G unit, and B unit The value is smaller than the voltage amplitude applied between the first contact electrode and the third contact electrode in the R unit, the G unit, and the B unit. 7. A full-color triode light-emitting tube display device according to claim 1, characterized in that the distributed Bragg reflective layers arranged in the R unit, the G unit and the B unit are all made of high refractive index and low Two films with refractive index are stacked, and the thickness of each layer is given by Determine, where n is the refractive index of the film, d is the film thickness, θ is the light incident angle, λ is the central wavelength, q is a constant, q≥0, and when q is a positive odd number, the reflectivity has an extreme value; set three The number of film stack layers of the distributed Bragg reflective layer are x, y, and z respectively, then all three are N or N+0.5, and N is a positive integer. 8. A full-color triode light-emitting tube display device according to claim 1, characterized in that the buffer layer, the first semiconductor layer, the second semiconductor layer, the third semiconductor layer, the blue light emitting layer, the third The four semiconductor layers are single-layer semiconductor structures with the same doping concentration, or multi-layer semiconductor structures with gradient or slowly changing doping concentrations. 9. A method for manufacturing a full-color triode light-emitting tube display device according to any one of claims 1 to 8, characterized in that it includes the following steps: sequentially growing a buffer layer, a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, a blue light emitting layer and a fourth semiconductor layer on the substrate; Etch the above layer to expose part of the second semiconductor layer to form an array module, and divide it into R units, G units and B units; Continue etching on the exposed second semiconductor layer until the first semiconductor layer is exposed; grow a first contact electrode on the exposed first semiconductor layer; and grow a second contact electrode on the exposed second semiconductor layer in the R unit, G unit, and B unit respectively; A third contact electrode is grown on the surface of the fourth semiconductor layer in the R unit, G unit, and B unit respectively; Prepare a red light color conversion layer and a green light color conversion layer on the surfaces of the third contact electrodes of the R unit and the G unit respectively; A distributed Bragg reflection layer is deposited on the red light color conversion layer, the green light color conversion layer of the R unit and the G unit, and the third contact electrode surface of the B unit respectively.