Display substrate, manufacturing method thereof and display device

Abstract

The invention provides a display substrate, a manufacturing method thereof and a display device. The display substrate comprises a driving backboard and a plurality of pixel structures arranged on the driving backboard. Each pixel structure comprises a red light chip, a green light chip and a blue light chip, and the red light chip, the green light chip and the blue light chip are arranged in a laminated mode. According to the display substrate, the red light chip, the green light chip and the blue light chip are arranged on the same substrate in a laminated mode, the size of the display substrate can be reduced, and cost is reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of display technology, and in particular to a display substrate and a manufacturing method thereof, and a display device. Background Art

[0002] LED (Lighting Emitting Diode) display devices have excellent display performance, which is mainly reflected in the fact that LED is an active light-emitting display with the characteristics of high brightness and high contrast, a narrower light spectrum, excellent color performance, and a response time that is much faster than the LCD (Liquid Crystal Display) technology that is currently used on a large scale.

[0003] Currently, LED display technology has been applied to AR (Augmented Reality) display scenarios. Ultra-high PPI (Pixels Per Inch, the number of pixels per inch of the screen diagonal) and ultra-high brightness LED display panels provide delicate and rich display images for AR displays.

[0004] The realization of high PPI LED colorization has always been a difficult problem in LED display technology. The existing silicon-based LED colorization solution uses the X-cube (color prism) solution, such as Figure 1 As shown, three single-color LED substrates realize color image splicing through X-cube prism. This solution does not fundamentally make the three-color LED chips on the same substrate. There are problems such as high alignment accuracy requirements between the LED substrate and the X-cube prism, increased size of the display device, and increased cost caused by the three LED substrates. Summary of the invention

[0005] The embodiments of the present invention provide a display substrate and a manufacturing method thereof, and a display device, which are used to solve the problems of high positioning accuracy requirement, large volume and high cost of existing LED display devices.

[0006] In order to solve the above-mentioned technical problems, the present invention is achieved as follows:

[0007] In a first aspect, an embodiment of the present invention provides a display substrate, comprising:

[0008] A driving backplane and a plurality of pixel structures disposed on the driving backplane;

[0009] Each of the pixel structures comprises: each of the pixel structures comprises: a red light chip, a green light chip and a blue light chip, and the red light chip, the green light chip and the blue light chip are stacked.

[0010] Optionally, the green chip and the blue chip are arranged on a side of the red chip away from the driving backplane, and the orthographic projections of the green chip and the blue chip on the driving backplane are both located within the orthographic projection area of ​​the red chip on the driving backplane.

[0011] Optionally, the green light chip and the blue light chip are arranged in the same layer.

[0012] Optionally, the green light chip includes a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer;

[0013] The blue light chip comprises a first doped semiconductor layer, a blue light emitting layer, and a second doped semiconductor layer;

[0014] The first doped semiconductor layer of the green light chip and the first doped semiconductor layer of the blue light chip are provided in the same layer and made of the same material;

[0015] The green light emitting layer of the green light chip is arranged on the same layer as the blue light emitting layer of the blue light chip;

[0016] The second doped semiconductor layer of the green light chip and the second doped semiconductor layer of the blue light chip are provided in the same layer and made of the same material.

[0017] Optionally, the green light chip includes a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer;

[0018] The blue light chip comprises a first doped semiconductor layer, a green light emitting layer, and a second doped semiconductor layer;

[0019] The first doped semiconductor layer of the green light chip and the first doped semiconductor layer of the blue light chip are provided in the same layer and made of the same material;

[0020] The green light emitting layer of the green light chip and the green light emitting layer of the blue light chip are provided in the same layer and with the same material;

[0021] The second doped semiconductor layer of the green light chip and the second doped semiconductor layer of the blue light chip are arranged in the same layer and made of the same material;

[0022] A surface of the second doped semiconductor layer of the blue light chip away from the green light emitting layer of the blue light chip is formed into a nanostructure, and the nanostructure causes the green light emitting layer of the blue light chip to blue-shift its luminous spectrum and emit blue light.

[0023] Optionally, in a direction away from the driving backplane, the red light chip, the green light chip and the blue light chip are stacked in sequence.

[0024] Optionally, the green light chip includes a light-emitting area and a non-light-emitting area located in the same layer;

[0025] The blue light chip is located on a side of the non-luminescent area away from the driving backplane, and its orthographic projection on the driving backplane does not overlap with the orthographic projection of the luminescent area on the driving backplane.

[0026] Optionally, the structure of the non-luminous area is the same as that of the luminous area, both including a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer, and the first doped semiconductor layer and the second doped semiconductor layer of the non-luminous area are both connected to the driving electrode or the common electrode on the driving backplane.

[0027] In a second aspect, an embodiment of the present invention provides a method for manufacturing a display substrate, characterized by comprising:

[0028] Provide drive backplane;

[0029] A plurality of pixel structures are formed on the driving backplane, wherein each of the pixel structures comprises: a red light chip, a green light chip and a blue light chip, and the red light chip, the green light chip and the blue light chip are stacked.

[0030] Optionally, the green chip and the blue chip are arranged on a side of the red chip away from the driving backplane, and the orthographic projections of the green chip and the blue chip on the driving backplane are both located within the orthographic projection area of ​​the red chip on the driving backplane.

[0031] Optionally, forming a plurality of pixel structures on the driving backplane includes:

[0032] Forming a red epitaxial wafer and a blue-green epitaxial wafer; wherein the red epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a red light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate; forming a blue-green epitaxial wafer comprises: providing an epitaxial substrate; forming a first doped semiconductor layer on the epitaxial substrate; placing a baffle in a first region of the epitaxial substrate having the first doped semiconductor layer, and forming one of a green light emitting layer and a blue light emitting layer in a second region of the epitaxial substrate having the first doped semiconductor layer; placing a baffle in the second region, and forming the other of a green light emitting layer and a blue light emitting layer in the first region; forming a second doped semiconductor layer on the epitaxial substrate forming the green light emitting layer and the blue light emitting layer;

[0033] Forming a common electrode layer on the surface of the second doped semiconductor layer of the red light epitaxial wafer or the blue-green light epitaxial wafer and bonding the red light epitaxial wafer or the blue-green light epitaxial wafer through the common electrode layer;

[0034] Peeling off the epitaxial substrate of the red light epitaxial wafer to obtain a red light chip layer, and bonding the red light chip layer to the driving backplane;

[0035] Peeling off the epitaxial substrate of the blue-green light epitaxial wafer to obtain a blue-green light chip layer;

[0036] forming a driving electrode layer on a side of the blue-green light chip layer away from the red light chip layer;

[0037] Etching the red light chip layer and the blue-green light chip layer to form an array structure of red light chips;

[0038] The blue-green light chip layer is etched to form an array structure of green light chips and blue light chips.

[0039] Optionally, forming a plurality of pixel structures on the driving backplane includes:

[0040] Forming a red epitaxial wafer and a green epitaxial wafer; the red epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a red light emitting layer and a second doped semiconductor layer disposed on the epitaxial substrate; the green epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer disposed on the epitaxial substrate;

[0041] forming a common electrode layer on the surface of the second doped semiconductor layer of the red epitaxial wafer or the green epitaxial wafer and bonding the red epitaxial wafer and the green epitaxial wafer via the common electrode layer;

[0042] Peeling off the epitaxial substrate of the red light epitaxial wafer to obtain a red light chip layer, and bonding the red light chip layer to the driving backplane;

[0043] The epitaxial substrate of the green light epitaxial wafer is peeled off to obtain a green light chip layer, and a surface of a partial area of ​​the first doped semiconductor layer of the green light chip layer is made into a nanostructure;

[0044] forming a driving electrode layer on a side of the green light chip layer away from the red light chip layer;

[0045] Etching the red light chip layer and the green light chip layer to form an array structure of red light chips;

[0046] The green chip layer is etched to form an array structure of green chips and blue chips, wherein the region of the green chip layer having the nanostructure forms a blue chip, and the region of the green chip layer not having the nanostructure forms a green chip.

[0047] Optionally, forming a plurality of pixel structures on the driving backplane includes:

[0048] A red epitaxial wafer, a green epitaxial wafer and a blue epitaxial wafer are formed; the red epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a red light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate; the green epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate; the blue epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate;

[0049] forming a common electrode layer on the surface of the second doped semiconductor layer of the red epitaxial wafer or the green epitaxial wafer and bonding the red epitaxial wafer and the green epitaxial wafer via the common electrode layer;

[0050] Peeling off the epitaxial substrate of the red light epitaxial wafer to obtain a red light chip layer, and bonding the red light chip layer to the driving backplane;

[0051] Peeling off the epitaxial substrate of the green light epitaxial wafer to obtain a green light chip layer;

[0052] Forming a first driving electrode layer on a side of the green light chip layer away from the red light chip layer, and bonding the green light epitaxial wafer and the blue light epitaxial wafer through the first driving electrode layer;

[0053] forming a second driving electrode layer on a side of the blue light chip layer away from the green light chip layer;

[0054] Etching the red light chip layer, the green light chip layer and the blue light chip layer to form an array structure of red light chips;

[0055] Etching the blue light chip layer to form an array structure of blue light chips;

[0056] The green light chip layer is etched to form an array structure of green light chips, wherein the green light chip includes a light-emitting area and a non-light-emitting area located in the same layer; the blue light chip is located on a side of the non-light-emitting area away from the driving backplane, and the orthographic projection of the blue light chip on the driving backplane does not overlap with the orthographic projection of the light-emitting area on the driving backplane, the structure of the non-light-emitting area is the same as that of the light-emitting area, both including a first doped semiconductor layer, a green light-emitting layer and a second doped semiconductor layer, and the first doped semiconductor layer and the second doped semiconductor layer of the non-light-emitting area are both connected to a common electrode on the driving backplane.

[0057] In a third aspect, an embodiment of the present invention provides a display device, comprising the display substrate as described in the first aspect.

[0058] In the embodiment of the present invention, the red light chip, the green light chip and the blue light chip are stacked on the same substrate, which can reduce the volume of the display substrate and reduce the cost, and is suitable for ultra-high PPI display devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0060] Figure 1 It is one of the structural schematic diagrams of a display substrate in the related art;

[0061] Figure 2 The second structural schematic diagram of a display substrate in the related art;

[0062] Figure 3 This is one of the structural schematic diagrams of a display substrate according to an embodiment of the present invention;

[0063] Figure 4 for Figure 3 A top view of the display substrate shown;

[0064] Figure 5 One of the schematic diagrams of the nanostructure according to an embodiment of the present invention;

[0065] Figure 6 This is a second schematic diagram of a nanostructure according to an embodiment of the present invention;

[0066] Figure 7 This is a second structural schematic diagram of a display substrate according to an embodiment of the present invention;

[0067] Figure 8 The third structural schematic diagram of the display substrate according to the embodiment of the present invention;

[0068] Fig. 9 This is a fourth structural schematic diagram of a display substrate according to an embodiment of the present invention;

[0069] Fig.10 FIG. 1 is a schematic diagram of a process of manufacturing a display substrate according to an embodiment of the present invention;

[0070] Fig.11 FIG2 is a second flow chart of a method for manufacturing a display substrate according to an embodiment of the present invention;

[0071] Figures 12 to 21 is a schematic diagram of a method for manufacturing a film layer of a display substrate according to an embodiment of the present invention;

[0072] Fig. 22FIG3 is a third flow chart of a method for manufacturing a display substrate according to an embodiment of the present invention;

[0073] Fig.23 The second schematic diagram of the method for manufacturing the film layer of the display substrate according to the embodiment of the present invention;

[0074] Fig.24 FIG. 4 is a fourth flow chart of a method for manufacturing a display substrate according to an embodiment of the present invention.

[0075] Fig.25 FIG. 5 is a fifth structural schematic diagram of a display substrate according to an embodiment of the present invention. DETAILED DESCRIPTION

[0076] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0077] Please refer to Figure 3 and Figure 4 An embodiment of the present invention provides a display substrate, comprising: a driving backplane 1 and a plurality of pixel structures arranged on the driving backplane 1; wherein each of the pixel structures comprises: a red light chip 2, a green light chip 3 and a blue light chip 4, and the red light chip 2, the green light chip 3 and the blue light chip 4 are stacked.

[0078] The driving backplane 1 generally includes a substrate and a driving circuit disposed on the substrate, and the driving circuit is used to drive the red light chip 2, the green light chip 3 and the blue light chip 4 to emit light. The substrate can be a glass substrate or a silicon-based substrate.

[0079] In the embodiment of the present invention, the red light chip, the green light chip and the blue light chip are stacked on the same substrate, which can reduce the volume of the display substrate and reduce the cost, and is suitable for ultra-high PPI display devices.

[0080] In traditional LED display substrates, in order to achieve colorization, only about one-third of the area in a pixel is used for red light chips, such as Figure 2As shown. It is well known that as the size of the red light chip decreases, the EQE (External Quantum Efficiency) decreases rapidly, that is, the size effect of the red light chip is more serious. When the size of the red light chip is reduced from about 100 microns to about a few microns, the efficiency decreases by about 100 times. The decrease in light efficiency means an increase in power consumption. In the scenario of AR display that needs to be driven by batteries, power consumption will be one of the important indicators for evaluating the quality of display devices; in addition, low efficiency means high heat generation, and the heat dissipation and life of the device will also face challenges.

[0081] Compared with the traditional LED display substrate, the X-cube (color prism) solution, please refer to Figure 1 Although the size of the red light chip is increased, this solution makes the three-color LED chips on three substrates respectively, which has problems such as high alignment accuracy requirements between the LED substrate and the X-cube prism, increased volume of the display device, and increased costs caused by the three LED substrates.

[0082] To solve the above problems, please refer to Figure 3 and Figure 4 The green light chip 3 and the blue light chip 4 are arranged on the side of the red light chip 2 away from the driving backplane, and the orthographic projections of the green light chip 3 and the blue light chip 4 on the driving backplane 1 are both located within the orthographic projection area of ​​the red light chip 2 on the driving backplane 1.

[0083] That is to say, the red light chip 2 is arranged at the bottom layer, and the green light chip 3 and the blue light chip 4 are arranged above the red light chip 2 .

[0084] In some embodiments of the present invention, optionally, the area of ​​the red light chip 2 is greater than the sum of the areas of the green light chip 3 and the blue light chip 4 .

[0085] In the embodiment of the present invention, the luminous area of ​​the red light chip can be maximized, so that the brightness and electro-optical conversion efficiency of the red light chip are maximized, and at the same time, the normal luminous area of ​​the blue light chip and the green light chip can be met (the same as the luminous area of ​​the existing blue light chip and the green light chip) or the luminous area can be increased, which can reduce the volume of the display substrate and reduce the cost, and can also improve the overall brightness of the pixel white light, which is suitable for ultra-high PPI display devices.

[0086] Of course, in some other embodiments of the present invention, the red light chip 2, the green light chip 3 and the blue light chip 4 may also adopt other stacked structures, such as Fig.25The red chip 2 and the green chip 3 are arranged in the same layer, and the blue chip 4 is arranged on the side of the red chip 2 and the green chip 3 away from the driving backplane 1. In this embodiment, the light-emitting area of ​​the blue chip can be maximized, so that the brightness and electro-optical conversion efficiency of the blue chip are maximized, and at the same time, the normal light-emitting area of ​​the red chip and the green chip (the same as the light-emitting area of ​​the existing blue chip and the green chip) can be met or the light-emitting area can be increased.

[0087] Alternatively, in some embodiments, the red light chip 2 and the blue light chip 4 may be arranged in the same layer, and the green light chip 3 may be arranged on the side of the red light chip 2 and the blue light chip 4 away from the driving backplane 1 to maximize the light-emitting area of ​​the green light chip.

[0088] Please refer to Figure 3 In the embodiment of the present invention, optionally, the red light chip 2 includes: a first doped semiconductor layer 21, a red light emitting layer 22 and a second doped semiconductor layer 23, wherein the first doped semiconductor layer 21 may be an N-type doped semiconductor layer, and the second doped semiconductor layer 23 may be a P-type doped semiconductor layer. Of course, in other embodiments, the first doped semiconductor layer 21 may also be a P-type doped semiconductor layer, and the second doped semiconductor layer 23 may be an N-type doped semiconductor layer.

[0089] Please refer to Figure 3 In the embodiment of the present invention, optionally, the green light chip 3 includes: a first doped semiconductor layer 31, a green light emitting layer 32 and a second doped semiconductor layer 33, wherein the first doped semiconductor layer 31 may be a P-type doped semiconductor layer, and the second doped semiconductor layer 33 may be an N-type doped semiconductor layer. Of course, in other embodiments, the first doped semiconductor layer 31 may also be an N-type doped semiconductor layer, and the second doped semiconductor layer 33 may be a P-type doped semiconductor layer.

[0090] Please refer to Figure 3 In the embodiment of the present invention, optionally, the blue light chip 4 includes: a first doped semiconductor layer 41, a blue light emitting layer 42 and a second doped semiconductor layer 43, wherein the first doped semiconductor layer 41 can be a P-type doped semiconductor layer (also referred to as a P-type doped layer), and the second doped semiconductor layer 43 can be an N-type doped semiconductor layer (also referred to as an N-type doped layer). Of course, in other embodiments, the first doped semiconductor layer 41 can also be an N-type doped semiconductor layer, and the second doped semiconductor layer 43 is a P-type doped semiconductor layer.

[0091] In the embodiment of the present invention, the red light chip may be made of an AlInGaP material system or other semiconductor material systems that can emit red light, and the green light chip and the blue light chip may be made of an InGaN material system.

[0092] In the embodiment of the present invention, optionally, the material of the N-type doping layer and the P-type doping layer of the green light chip and / or the blue light chip may be GaN. The N-type doping layer may be expressed as N-GaN.

[0093] In the embodiment of the present invention, the red light chip, the green light chip and the blue light chip in a single pixel are driven and displayed independently.

[0094] In order to drive the red light chip 2 to emit light, in the embodiment of the present invention, the display substrate further includes: a first electrode 5a, a second electrode 5b, a first conductive layer pattern 6a and a third electrode 7, wherein the first electrode 5a may be an N electrode, connected to the first doped semiconductor layer 21 (in this embodiment, an N-type doped semiconductor layer) of the red light chip 2, and the second electrode 5b may be a P electrode, connected to the second doped semiconductor layer 23 (in this embodiment, a P-type doped semiconductor layer) of the red light chip 2 through the first conductive layer pattern 6a and the third electrode 7 (also referred to as a P electrode). In the embodiment of the present invention, the first electrode 5a may be a driving electrode, and the second electrode 5b and the third electrode 7 may be common electrodes, and the driving voltage and driving current are formed by the voltage difference between the driving electrode and the common electrode. In some other examples, if the first doped semiconductor layer 21 of the red light chip 2 is a P-type doped semiconductor layer and the second doped semiconductor layer 23 is an N-type doped semiconductor layer, the first electrode 5a is a P electrode, and the second electrode 5b and the third electrode 7 are N electrodes.

[0095] In order to drive the green chip 3 to emit light, in the embodiment of the present invention, the display substrate further includes: a fourth electrode 5c, a second conductive layer pattern 6b and a fifth electrode 8a, wherein the fourth electrode 5c may be an N electrode, connected to the second doped semiconductor layer 33 (in this embodiment, an N-type doped semiconductor layer) of the green chip 3 through the second conductive layer pattern 6b and the fifth electrode 8a. In the embodiment of the present invention, in order to reduce the thickness of the display substrate, the first doped semiconductor layer 31 (in this embodiment, a P-type doped semiconductor layer) of the green chip 3 and the second doped semiconductor layer 23 (in this embodiment, a P-type doped semiconductor layer) of the red chip 2 share the second electrode 5b, the first conductive layer pattern 6a and the third electrode 7, that is, the first doped semiconductor layer 31 of the green chip 3 is connected to the second electrode 5b through the third electrode 7 and the first conductive layer pattern 6a. In the embodiment of the present invention, the fourth electrode 5c is an N electrode and a driving electrode, and the second electrode 5b and the third electrode 7 are P electrodes and common electrodes. In some other examples, if the first doped semiconductor layer 31 of the green light chip 3 is an N-type doped semiconductor layer and the second doped semiconductor layer 33 is a P-type doped semiconductor layer, the fourth electrode 5c is a P-electrode and a driving electrode, and the second electrode 5b and the third electrode 7 are N-electrodes and common electrodes.

[0096] In order to drive the blue light chip 4 to emit light, in the embodiment of the present invention, the display substrate further includes: a sixth electrode 5d, a third conductive layer pattern 6c and a seventh electrode 8b, wherein the sixth electrode 5d may be an N electrode, connected to the second doped semiconductor layer 43 (in this embodiment, an N-type doped semiconductor layer) of the blue light chip 4 through the third conductive layer pattern 6c and the seventh electrode 8b. In the embodiment of the present invention, in order to reduce the thickness of the display substrate, the first doped semiconductor layer 41 (in this embodiment, a P-type doped semiconductor layer) of the blue light chip 4 and the second doped semiconductor layer 23 (in this embodiment, a P-type doped semiconductor layer) of the red light chip 2 share the second electrode 5b, the first conductive layer pattern 6a and the third electrode 7, that is, the first doped semiconductor layer 41 of the blue light chip 4 is connected to the second electrode 5b through the third electrode 7 and the first conductive layer pattern 6a. In the embodiment of the present invention, the sixth electrode 5d is an N electrode and a driving electrode, and the second electrode 5b and the third electrode 7 are P electrodes and common electrodes. In some other examples, if the first doped semiconductor layer 41 of the blue light chip 4 is an N-type doped semiconductor layer and the second doped semiconductor layer 43 is a P-type doped semiconductor layer, then the sixth electrode 5d is a P-electrode and a driving electrode, and the second electrode 5b and the third electrode 7 are N-electrodes and are common electrodes.

[0097] In the embodiment of the present invention, by controlling whether the N electrode on the driving backplane is turned on or off, and controlling whether each chip is turned on or off, the pixels can be driven to achieve color display, and grayscale can be achieved by controlling the conduction time of the N electrode, that is, turning on pulse width control.

[0098] Please refer to Figure 3 In the embodiment of the present invention, optionally, the green light chip 3 and the blue light chip 4 are arranged in the same layer. Figure 3In the embodiment shown, the first doped semiconductor layer 31 of the green chip 3 is arranged in the same layer and the same material as the first doped semiconductor layer 41 of the blue chip 4; the green light emitting layer 32 of the green chip 3 is arranged in the same layer and the same material as the green light emitting layer 42 of the blue chip 4; the second doped semiconductor layer 33 of the green chip 3 is arranged in the same layer and the same material as the second doped semiconductor layer 43 of the blue chip 4; the second doped semiconductor layer 43 of the blue chip 4 is formed into a nanostructure 431 on the side of the surface away from the green light emitting layer 42 of the blue chip 4, and the nanostructure 431 can change the current distribution of the second doped semiconductor layer 43 of the blue chip 4, so that the local current density is increased, and the influence of the quantum Stark effect is eliminated, so that the luminescence spectrum of the green light emitting layer 42 of the blue chip 4 is blue-shifted to emit blue light. The quantum Stark effect refers to the phenomenon that in a quantum well structure, the semiconductor energy band is tilted due to factors such as lattice stress, causing the luminescence peak to red-shift. Therefore, by constructing a strong internal electric field force to offset the influence of lattice stress, the originally red-shifted spectrum is blue-shifted, achieving blue light emission.

[0099] The nanostructure 431 in the embodiment of the present invention can be as follows Figure 5 and Figure 6 As shown, the nanostructure 431 includes a plurality of arrayed nanographs, and the nanographs may be circular, square, or linear structures, or other shapes, which are not limited in the present invention. In the embodiment of the present invention, the arrangement period of the nanographs may be about 1 μm, for example, when the nanographs are circular, the diameter may be less than 1 μm.

[0100] In the embodiment of the present invention, the thickness of the second doped semiconductor layer 43 (eg, N-type doped layer) of the blue light chip 4 may be between 0.5 μm and 2 μm (including the height of the nanostructure), wherein the height of the nanostructure may be between 200 and 500 nm.

[0101] Optionally, the nanostructure 431 is formed by performing a nanoimprint process on a surface of the second doped semiconductor layer 43 that is away from the green light emitting layer 42 of the blue light chip 4 .

[0102] In the embodiment of the present invention, the light-emitting layer of the blue light chip 4 is a green light-emitting layer, which can be formed simultaneously with the green light-emitting layer of the green light chip 3 to save process. In order to emit blue light, a nanostructure is formed on the second doped semiconductor layer 43 so that the light-emitting spectrum of the green light-emitting layer 42 of the blue light chip 4 is blue-shifted.

[0103] Please refer to Figure 7 In another embodiment of the present invention, optionally, the green light chip 3 and the blue light chip 4 are arranged in the same layer. Figure 3In the embodiment shown, the first doped semiconductor layer 31 of the green chip 3 is arranged in the same layer and the same material as the first doped semiconductor layer 41 of the blue chip 4; the green light emitting layer 32 of the green chip 3 is arranged in the same layer as the blue light emitting layer 42 of the blue chip 4; the second doped semiconductor layer 33 of the green chip 3 is arranged in the same layer and the same material as the second doped semiconductor layer 43 of the blue chip 4. In this embodiment, the blue light emitting layer 42 of the blue chip 4 emits blue light, so there is no need to make a nanostructure on the second doped semiconductor layer 43.

[0104] Figure 3 and Figure 7 In the embodiment shown, the red chip area accounts for the largest proportion, which is larger than the sum of the green chip area and the blue chip area. The area of ​​the green chip can be the same as the area of ​​the blue chip, or different area proportions can be adjusted according to the white light demand, but it is necessary to ensure that the projection of the display area of ​​the blue and green chips is within the display area of ​​the red chip.

[0105] Please refer to Figure 8 In another embodiment of the present invention, in a direction away from the driving backplane 1, the red light chip 2, the green light chip 3 and the blue light chip 4 are stacked in sequence.

[0106] Please refer to Figure 8 In one embodiment, the green light chip 3 includes a light-emitting area and a non-light-emitting area located on the same layer; the blue light chip 4 is located on a side of the non-light-emitting area away from the driving backplane 1, and its orthographic projection on the driving backplane 1 does not overlap with the orthographic projection of the light-emitting area on the driving backplane 1.

[0107] In an embodiment of the present invention, optionally, the structure of the non-luminous area is the same as that of the luminous area, both including a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer, and the first doped semiconductor layer and the second doped semiconductor layer of the non-luminous area are both connected to the driving electrode or the common electrode on the driving backplane 1.

[0108] Figure 8In the embodiment shown, in order to drive the red light chip 2 to emit light, in the embodiment of the present invention, the display substrate further includes: a first electrode 5a, a second electrode 5b, a first conductive layer pattern 6a and a third electrode 7, wherein the first electrode 5a may be an N electrode, connected to the first doped semiconductor layer 21 (in this embodiment, an N-type doped semiconductor layer) of the red light chip 2, and the second electrode 5b may be a P electrode, connected to the second doped semiconductor layer 23 (in this embodiment, a P-type doped semiconductor layer) of the red light chip 2 through the first conductive layer pattern 6a and the third electrode 7 (also referred to as a P electrode). In the embodiment of the present invention, the first electrode 5a may be a driving electrode, and the second electrode 5b and the third electrode 7 may be common electrodes. In some other examples, if the first doped semiconductor layer 21 of the red light chip 2 is a P-type doped semiconductor layer and the second doped semiconductor layer 23 is an N-type doped semiconductor layer, the first electrode 5a is a P electrode, and the second electrode 5b and the third electrode 7 are N electrodes.

[0109] Figure 8In the embodiment shown, in order to drive the green chip 3 to emit light, in the embodiment of the present invention, the display substrate further includes: a fourth electrode 5c, a second conductive layer pattern 6b and a fifth electrode 8a, wherein the fourth electrode 5c may be an N electrode, connected to the second doped semiconductor layer 33 (in this embodiment, an N-type doped semiconductor layer) of the light-emitting region of the green chip 3 through the second conductive layer pattern 6b and the fifth electrode 8a. In the embodiment of the present invention, in order to reduce the thickness of the display substrate, the first doped semiconductor layer 31 (in this embodiment, a P-type doped semiconductor layer) of the light-emitting region of the green chip 3 and the second doped semiconductor layer 23 (in this embodiment, a P-type doped semiconductor layer) of the red chip 2 share the second electrode 5b, the first conductive layer pattern 6a and the third electrode 7, that is, the first doped semiconductor layer 31 of the light-emitting region of the green chip 3 is connected to the second electrode 5b through the third electrode 7 and the first conductive layer pattern 6a. In the embodiment of the present invention, the fourth electrode 5c is an N electrode and a driving electrode, and the second electrode 5b and the third electrode 7 are P electrodes and common electrodes. In some other examples, if the first doped semiconductor layer 31 of the light-emitting region of the green chip 3 is an N-type doped semiconductor layer, and the second doped semiconductor layer 33 is a P-type doped semiconductor layer, the fourth electrode 5c is a P-electrode and a driving electrode, and the second electrode 5b and the third electrode 7 are N-electrodes and common electrodes. In addition, the display substrate further includes: an eighth electrode 5e, a fourth conductive layer pattern 6d and a ninth electrode 8c, wherein the eighth electrode 5e may be a P-electrode, connected to the second doped semiconductor layer (the N-type doped semiconductor layer in this embodiment) of the non-light-emitting region of the green chip 3 through the fourth conductive layer pattern 6d and the ninth electrode 8c, and the first doped semiconductor layer (the P-type doped semiconductor layer in this embodiment) of the non-light-emitting region of the green chip 3 and the second doped semiconductor layer 23 (the P-type doped semiconductor layer in this embodiment) of the red chip 2 share the second electrode 5b, the first conductive layer pattern 6a and the third electrode 7, that is, the first doped semiconductor layer of the non-light-emitting region of the green chip 3 is connected to the second electrode 5b through the third electrode 7 and the first conductive layer pattern 6a. Since the eighth electrode 5e and the second electrode 5b are both P electrodes, no driving current is generated between the eighth electrode 5e and the second electrode 5b, so that the non-luminescent area does not emit light.

[0110] Figure 8In the embodiment shown, in order to drive the blue light chip 4 to emit light, in the embodiment of the present invention, the display substrate further includes: a sixth electrode 5d, a third conductive layer pattern 6c and a seventh electrode 8b, wherein the sixth electrode 5d may be an N electrode, connected to the second doped semiconductor layer 43 (in this embodiment, an N-type doped semiconductor layer) of the blue light chip 4 through the third conductive layer pattern 6c and the seventh electrode 8b. In the embodiment of the present invention, in order to reduce the thickness of the display substrate, the first doped semiconductor layer 41 (in this embodiment, a P-type doped semiconductor layer) of the blue light chip 4 and the second doped semiconductor layer of the non-luminous region of the green light chip 3 share the eighth electrode 5e, the fourth conductive layer pattern 6d and the ninth electrode 8c, that is, the first doped semiconductor layer 41 of the blue light chip 4 is connected to the eighth electrode 5e through the fourth conductive layer pattern 6d and the ninth electrode 8c. In the embodiment of the present invention, the sixth electrode 5d is an N electrode and a driving electrode, and the eighth electrode 5e and the ninth electrode 8c are P electrodes and common electrodes.

[0111] The blue and green chips above the red chip emit light, and part of the light propagates downward to the red chip. To avoid this part of the blue-green light from photoexciting the red chip and causing color deviation when displaying colors, please refer to Fig. 9 , a DBR layer 14 can be formed between the red light chip and the blue and green light chips. DBR is also called a distributed Bragg reflector. The DBR structure is composed of alternating multiple layers of high refractive index and low refractive index materials. For example, the DBR layer 14 in the embodiment of the present invention can be composed of multiple layers of titanium oxide and silicon oxide, and has the function of transmitting red light and reflecting blue and green light. It should be noted that at this time, the electrode 7a (such as the ITO layer) on the red light chip and the electrode 7b (such as the ITO layer) on the blue and green light chip are no longer shared and no longer in direct contact. Therefore, it is necessary to etch the electrodes 7a, 7b and the DBR layer 14 into a step structure to ensure that the first conductive layer pattern 6a can contact the upper electrodes 7a and 7b at the same time to achieve consistent signals of the electrodes 7a and 7b.

[0112] In the above embodiment of the present invention, the display substrate may further include: a first insulating layer 10, which is used to prevent the conductive layer pattern (the first conductive layer pattern 6a, the second conductive layer pattern 6b or the third conductive layer pattern 6c) from contacting the side wall of the chip to cause a short circuit of the chip (please refer to Figure 3 and Figure 7 ), and to prevent the blue chip 4 and the green chip 3 from contacting each other and causing a chip short circuit (please refer to Figure 3 and Figure 7 ).

[0113] In the above embodiment of the present invention, the display substrate may further include: a second insulating layer 11, which is used for contact between conductive layer patterns (such as the first conductive layer pattern 6a and the third conductive layer pattern 6c).

[0114] In the embodiment of the present invention, the first insulating layer and / or the second insulating layer may be made of materials such as silicon oxide and silicon nitride.

[0115] In the above embodiment of the present invention, the display substrate may further include: a flat layer 12 for covering the pixel structure. In the embodiment of the present invention, the flat layer may be an organic glue material. It is worth noting that in order to avoid the adverse effect of the viewing angle caused by the side light emission of the chip, black carbon powder may be doped in the organic glue (flat layer) to achieve the purpose of absorbing the side light emission.

[0116] In the above embodiment of the present invention, the display substrate may further include: an encapsulation layer 13 for encapsulating the pixel structure. In the embodiment of the present invention, the encapsulation layer 13 may be encapsulation glass or encapsulation glue, which plays a role in protecting the chip structure and the conductive layer.

[0117] In the above embodiment of the present invention, optionally, the pixel structure may be a square, so that a display substrate with a high PPI can be obtained.

[0118] An embodiment of the present invention further provides a display device, comprising the display substrate in any one of the above embodiments.

[0119] Please refer to Fig.10 The embodiment of the present invention further provides a method for manufacturing a display substrate, comprising:

[0120] Step S1: providing a driving backplane;

[0121] Step S2: forming a plurality of pixel structures on the driving backplane, wherein each of the pixel structures comprises: a red light chip, a green light chip and a blue light chip, and the red light chip, the green light chip and the blue light chip are stacked.

[0122] Optionally, the green light chip and the blue light chip are arranged on a side of the red light chip away from the driving backplane, and the orthographic projections of the green light chip and the blue light chip on the driving backplane are both located within the orthographic projection area of ​​the red light chip on the driving backplane.

[0123] In the embodiment of the present invention, when the PPI is low and the pixel size is relatively large, the bonding of a single chip can be achieved by transfer, thereby achieving Figure 3 , Figure 7 When the PPI is too high and the chip size is too small, it is impossible to transfer a single chip, and the transfer and bonding can only be done on the epitaxial substrate as a unit. Therefore, it is necessary to form a green chip and a blue chip on the same substrate.

[0124] Optionally, in one embodiment, please refer to Fig.11 , forming a plurality of pixel structures on the driving backplane includes:

[0125] Step S21': Please refer to Fig.12 , forming a red epitaxial wafer and a green epitaxial wafer; the red epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer ( Fig.11 In the embodiment shown, the N-type doped layer), the red light emitting layer (red MQW layer) and the second doped semiconductor layer ( Fig.11 In the embodiment shown, the green light epitaxial wafer includes an epitaxial substrate and a first doped semiconductor layer ( Fig.11 In the embodiment shown, the N-type doped layer), the green light emitting layer (green MQW layer) and the second doped semiconductor layer ( Fig.11 In the embodiment shown, it is a P-type doped layer);

[0126] Step S22': Please refer to Fig.13 , forming a common electrode layer (ITO layer) on the surface of the second doped semiconductor layer of the red epitaxial wafer or the green epitaxial wafer and bonding the red epitaxial wafer and the green epitaxial wafer through the common electrode layer;

[0127] Step S23': Please refer to Fig.14 , peeling off the epitaxial substrate of the red light epitaxial wafer to obtain a red light chip layer, and bonding the red light chip layer to the driving backplane;

[0128] Step S24': Please refer to Fig.14 , peeling off the epitaxial substrate of the green light epitaxial wafer to obtain a green light chip layer, and making a nanostructure on a partial surface of a first doped semiconductor layer (an N-type doped layer in this embodiment) of the green light chip layer;

[0129] In the embodiment of the present invention, after the epitaxial substrate of the green light epitaxial wafer is formed, the first doped semiconductor layer (the N-type doped layer in this embodiment) of the green light chip layer may be thinned.

[0130] In the embodiment of the present invention, the green light epitaxial wafer is doped with In content ratio according to the conventional green light chip. After the green light epitaxial wafer is transferred, the substrate is peeled off, the first doped semiconductor layer is thinned, and then the first doped semiconductor layer (the N-type doped layer in this embodiment) in the area where the blue light chip is to be formed is subjected to nanostructure treatment, thereby changing its current distribution, increasing the local current density, eliminating the influence of the Stark effect, and blue-shifting the luminescent spectrum to emit blue light.

[0131] Step S25': Please refer to Fig.14 , forming a driving electrode layer (an ITO layer in this embodiment) on a side of the green light chip layer away from the red light chip layer;

[0132] Step S26': Please refer to Fig.15 , etching the red light chip layer and the green light chip layer to form an array structure of red light chips;

[0133] Step S27': Please refer to Fig.16 , etching the green chip layer to form an array structure of green chips and blue chips, wherein the area of ​​the green chip layer with the nanostructure forms a blue chip, and the area of ​​the green chip layer without the nanostructure forms a green chip.

[0134] In the embodiment of the present invention, the method may further include:

[0135] Step S28': Please refer to Fig.17 , forming a pattern of a first insulating layer, and the first insulating layer covers the periphery of each chip.

[0136] Step S29': Please refer to Fig.18 , forming a first conductive layer pattern.

[0137] Step S210': Please refer to Fig.19 , forming a pattern of a second insulating layer.

[0138] Step S211': Please refer to Fig. 20 , forming a second conductive layer pattern.

[0139] Step S212': Please refer to Fig.21 , forming a planarization layer and an encapsulation layer.

[0140] In an embodiment of the present invention, the thickness of the P-type doped layer is about 150nm, the thickness of the light-emitting layer (MQW, multi-quantum well layer) is about 150nm, the N-type doped layer can be thinned to 800nm, the thickness of the ITO layer is about 100nm, and the conductive layer can be metal (Al, Ag) or ITO with a thickness of about 100nm. The total thickness of the device is approximately: 800+150+150+100+100+150+150+800+100=2500nm.

[0141] In general, the minimum size of a red chip can be about 6μm. The overall size of a red chip is 6μm*6μm, and the height is about 2.5μm. Relative to the area, the device height is smaller, making it less likely to have process problems such as chip tipping or poor etching due to excessive etching depth (the height of the device is the total thickness of the film layer. After wafer-level bonding, pixel etching is required, and the maximum etching thickness is the total thickness of the film layer. As the film thickness increases, the etching depth-to-width ratio increases, which increases the difficulty of process manufacturing), and will not lead to a decrease in device yield. However, the size of blue and green chips can be no larger than 5μm*2.5μm, for example, 4μm*2μm.

[0142] Optionally, in one embodiment, please refer to Fig. 22 , forming a plurality of pixel structures on the driving backplane includes:

[0143] Step S21: forming a red epitaxial wafer and a blue-green epitaxial wafer; wherein the red epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a red light emitting layer and a second doped semiconductor layer disposed on the epitaxial substrate; please refer to Fig.23 , forming a blue-green epitaxial wafer includes: providing an epitaxial substrate; forming a first doped semiconductor layer (an N-type doped layer in this embodiment) on the epitaxial substrate; placing a baffle (i.e., a metal baffle in the figure) in a first region of the epitaxial substrate having the first doped semiconductor layer, and forming one of a green light emitting layer and a blue light emitting layer in a second region of the epitaxial substrate having the first doped semiconductor layer; placing a baffle in the second region, and forming the other of a green light emitting layer and a blue light emitting layer in the first region; forming a second doped semiconductor layer (a P-type doped layer in this embodiment) on the epitaxial substrate forming the green light emitting layer and the blue light emitting layer;

[0144] Step S22: forming a common electrode layer on the surface of the second doped semiconductor layer of the red epitaxial wafer or the blue-green epitaxial wafer and bonding the red epitaxial wafer or the blue-green epitaxial wafer through the common electrode layer;

[0145] The common electrode layer can be formed of transparent conductive materials such as ITO.

[0146] Step S23: peeling off the epitaxial substrate of the red light epitaxial wafer to obtain a red light chip layer, and bonding the red light chip layer to the driving backplane;

[0147] After stripping the epitaxial substrate of the red light epitaxial wafer, the method may further include: thinning the first doped semiconductor layer of the red light epitaxial wafer.

[0148] Step S24: peeling off the epitaxial substrate of the blue-green light epitaxial wafer to obtain a blue-green light chip layer;

[0149] Step S25: forming a driving electrode layer on a side of the blue-green light chip layer away from the red light chip layer;

[0150] Step S26: etching the red light chip layer and the blue-green light chip layer to form an array structure of red light chips;

[0151] Step S27: etching the blue-green chip layer to form an array structure of green light chips and blue light chips.

[0152] In the embodiment of the present invention, the nanostructure manufacturing process can be omitted, the N-type doping layer materials of the blue and green chips are consistent, the MQW layer materials are different, and the P-type doping layer materials are consistent. There may be a transition area of ​​In content at the junction of the regional growth MQW. During pixel etching, the transition area can be etched away and filled with an insulating layer, which will not affect the light output spectrum and light output efficiency of the light-emitting area of ​​the blue and green chips.

[0153] Optionally, in one embodiment, please refer to Fig.24 , forming a plurality of pixel structures on the driving backplane includes:

[0154] Step S21”: forming a red epitaxial wafer, a green epitaxial wafer and a blue epitaxial wafer; the red epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a red light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate; the green epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate; the blue epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate;

[0155] Step S22″: forming a common electrode layer on the surface of the second doped semiconductor layer of the red epitaxial wafer or the green epitaxial wafer and bonding the red epitaxial wafer and the green epitaxial wafer via the common electrode layer;

[0156] Step S23″: peeling off the epitaxial substrate of the red light epitaxial wafer to obtain a red light chip layer, and bonding the red light chip layer to the driving backplane;

[0157] Step S24": peeling off the epitaxial substrate of the green light epitaxial wafer to obtain a green light chip layer;

[0158] Step S25″: forming a first driving electrode layer on a side of the green light chip layer away from the red light chip layer, and bonding the green light epitaxial wafer and the blue light epitaxial wafer through the first driving electrode layer;

[0159] Step S26″: forming a second driving electrode layer on a side of the blue light chip layer away from the green light chip layer;

[0160] Step S27″: etching the red light chip layer, the green light chip layer and the blue light chip layer to form an array structure of red light chips;

[0161] Step S28": etching the blue light chip layer to form an array structure of blue light chips;

[0162] Step S29": etching the green light chip layer to form an array structure of green light chips, wherein the green light chip includes a light-emitting area and a non-light-emitting area located in the same layer; the blue light chip is located on a side of the non-light-emitting area away from the driving backplane, and the orthographic projection on the driving backplane does not overlap with the orthographic projection of the light-emitting area on the driving backplane, the structure of the non-light-emitting area is the same as that of the light-emitting area, both including a first doped semiconductor layer, a green light-emitting layer and a second doped semiconductor layer, and the first doped semiconductor layer and the second doped semiconductor layer of the non-light-emitting area are both connected to a common electrode on the driving backplane.

[0163] In the embodiment of the present invention, the blue light chip and the green light chip are non-same-layer structures, that is, the green light epitaxial wafer is first bonded to the red light epitaxial wafer, and then the blue light epitaxial wafer is bonded to the surface of the green light epitaxial wafer. The green light epitaxial wafer is cut into two areas within a pixel, including a light-emitting area and a non-light-emitting area. Adjusting the ratio of the two areas can control the light-emitting area of ​​the green light.

[0164] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A display substrate, characterized in that: include: A driving backplane and a plurality of pixel structures disposed on the driving backplane; Each of the pixel structures comprises: a red light chip, a green light chip and a blue light chip, and the red light chip, the green light chip and the blue light chip are stacked.

2. The display substrate according to claim 1, characterized in that: The green light chip and the blue light chip are arranged on a side of the red light chip away from the driving backplane, and the orthographic projections of the green light chip and the blue light chip on the driving backplane are both located within the orthographic projection area of ​​the red light chip on the driving backplane.

3. The display substrate according to claim 2, characterized in that: The green light chip and the blue light chip are arranged in the same layer.

4. The display substrate according to claim 3, characterized in that: The green light chip comprises a first doped semiconductor layer, a green light emitting layer, and a second doped semiconductor layer; The blue light chip comprises a first doped semiconductor layer, a blue light emitting layer, and a second doped semiconductor layer; The first doped semiconductor layer of the green light chip and the first doped semiconductor layer of the blue light chip are provided in the same layer and made of the same material; The green light emitting layer of the green light chip is arranged on the same layer as the blue light emitting layer of the blue light chip; The second doped semiconductor layer of the green light chip and the second doped semiconductor layer of the blue light chip are provided in the same layer and made of the same material.

5. The display substrate according to claim 3, characterized in that: The green light chip comprises a first doped semiconductor layer, a green light emitting layer, and a second doped semiconductor layer; The blue light chip comprises a first doped semiconductor layer, a green light emitting layer, and a second doped semiconductor layer; The first doped semiconductor layer of the green light chip and the first doped semiconductor layer of the blue light chip are provided in the same layer and made of the same material; The green light emitting layer of the green light chip and the green light emitting layer of the blue light chip are provided in the same layer and with the same material; The second doped semiconductor layer of the green light chip and the second doped semiconductor layer of the blue light chip are arranged in the same layer and made of the same material; A surface of the second doped semiconductor layer of the blue light chip away from the green light emitting layer of the blue light chip is formed into a nanostructure, and the nanostructure causes the green light emitting layer of the blue light chip to blue-shift its luminous spectrum and emit blue light.

6. The display substrate according to claim 2, characterized in that: In a direction away from the driving backplane, the red light chip, the green light chip and the blue light chip are stacked in sequence.

7. The display substrate according to claim 6, characterized in that: The green light chip includes a light-emitting area and a non-light-emitting area located in the same layer; The blue light chip is located on a side of the non-luminescent area away from the driving backplane, and its orthographic projection on the driving backplane does not overlap with the orthographic projection of the luminescent area on the driving backplane.

8. The display substrate according to claim 7, characterized in that: The structure of the non-luminous area is the same as that of the luminous area, both of which include a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer. The first doped semiconductor layer and the second doped semiconductor layer of the non-luminous area are both connected to the driving electrode or the common electrode on the driving backplane.

9. A method for manufacturing a display substrate, characterized in that: include: Provide drive backplane; A plurality of pixel structures are formed on the driving backplane, wherein each of the pixel structures comprises: a red light chip, a green light chip and a blue light chip, and the red light chip, the green light chip and the blue light chip are stacked.

10. The method for manufacturing a display substrate according to claim 9, characterized in that: The green light chip and the blue light chip are arranged on a side of the red light chip away from the driving backplane, and the orthographic projections of the green light chip and the blue light chip on the driving backplane are both located within the orthographic projection area of ​​the red light chip on the driving backplane.

11. The method for manufacturing a display substrate according to claim 10, characterized in that: Forming a plurality of pixel structures on the driving backplane includes: Forming a red epitaxial wafer and a blue-green epitaxial wafer; wherein the red epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a red light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate; forming a blue-green epitaxial wafer comprises: providing an epitaxial substrate; forming a first doped semiconductor layer on the epitaxial substrate; placing a baffle in a first region of the epitaxial substrate having the first doped semiconductor layer, and forming one of a green light emitting layer and a blue light emitting layer in a second region of the epitaxial substrate having the first doped semiconductor layer; placing a baffle in the second region, and forming the other of a green light emitting layer and a blue light emitting layer in the first region; forming a second doped semiconductor layer on the epitaxial substrate forming the green light emitting layer and the blue light emitting layer; Forming a common electrode layer on the surface of the second doped semiconductor layer of the red light epitaxial wafer or the blue-green light epitaxial wafer and bonding the red light epitaxial wafer or the blue-green light epitaxial wafer through the common electrode layer; Peeling off the epitaxial substrate of the red light epitaxial wafer to obtain a red light chip layer, and bonding the red light chip layer to the driving backplane; Peeling off the epitaxial substrate of the blue-green light epitaxial wafer to obtain a blue-green light chip layer; forming a driving electrode layer on a side of the blue-green light chip layer away from the red light chip layer; Etching the red light chip layer and the blue-green light chip layer to form an array structure of red light chips; The blue-green light chip layer is etched to form an array structure of green light chips and blue light chips.

12. The method for manufacturing a display substrate according to claim 10, characterized in that: Forming a plurality of pixel structures on the driving backplane includes: Forming a red epitaxial wafer and a green epitaxial wafer; the red epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a red light emitting layer and a second doped semiconductor layer disposed on the epitaxial substrate; the green epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer disposed on the epitaxial substrate; forming a common electrode layer on the surface of the second doped semiconductor layer of the red epitaxial wafer or the green epitaxial wafer and bonding the red epitaxial wafer and the green epitaxial wafer via the common electrode layer; Peeling off the epitaxial substrate of the red light epitaxial wafer to obtain a red light chip layer, and bonding the red light chip layer to the driving backplane; The epitaxial substrate of the green light epitaxial wafer is peeled off to obtain a green light chip layer, and a surface of a partial area of ​​the first doped semiconductor layer of the green light chip layer is made into a nanostructure; forming a driving electrode layer on a side of the green light chip layer away from the red light chip layer; Etching the red light chip layer and the green light chip layer to form an array structure of red light chips; The green chip layer is etched to form an array structure of green chips and blue chips, wherein the region of the green chip layer having the nanostructure forms a blue chip, and the region of the green chip layer not having the nanostructure forms a green chip.

13. The method for manufacturing a display substrate according to claim 10, characterized in that: Forming a plurality of pixel structures on the driving backplane includes: A red epitaxial wafer, a green epitaxial wafer and a blue epitaxial wafer are formed; the red epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a red light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate; the green epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate; the blue epitaxial wafer comprises an epitaxial substrate and a first doped semiconductor layer, a green light emitting layer and a second doped semiconductor layer arranged on the epitaxial substrate; forming a common electrode layer on the surface of the second doped semiconductor layer of the red epitaxial wafer or the green epitaxial wafer and bonding the red epitaxial wafer and the green epitaxial wafer via the common electrode layer; Peeling off the epitaxial substrate of the red light epitaxial wafer to obtain a red light chip layer, and bonding the red light chip layer to the driving backplane; Peeling off the epitaxial substrate of the green light epitaxial wafer to obtain a green light chip layer; Forming a first driving electrode layer on a side of the green light chip layer away from the red light chip layer, and bonding the green light epitaxial wafer and the blue light epitaxial wafer through the first driving electrode layer; forming a second driving electrode layer on a side of the blue light chip layer away from the green light chip layer; Etching the red light chip layer, the green light chip layer and the blue light chip layer to form an array structure of red light chips; Etching the blue light chip layer to form an array structure of blue light chips; The green light chip layer is etched to form an array structure of green light chips, wherein the green light chip includes a light-emitting area and a non-light-emitting area located in the same layer; the blue light chip is located on a side of the non-light-emitting area away from the driving backplane, and the orthographic projection of the blue light chip on the driving backplane does not overlap with the orthographic projection of the light-emitting area on the driving backplane, the structure of the non-light-emitting area is the same as that of the light-emitting area, both including a first doped semiconductor layer, a green light-emitting layer and a second doped semiconductor layer, and the first doped semiconductor layer and the second doped semiconductor layer of the non-light-emitting area are both connected to a common electrode on the driving backplane.

14. A display device, characterized in that: The display substrate comprises the display substrate as claimed in any one of claims 1 to 8.

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