Display panel and display device

Abstract

The invention discloses a display panel and a display device. The display panel comprises a substrate and at least one light-emitting structure arranged on the substrate, the light-emitting structure comprises a first light-emitting part and a color conversion light-emitting part, and the first light-emitting part comprises a first color light-emitting layer; the color conversion light-emitting part and the first light-emitting part are stacked on the substrate in the first direction, the first direction is the direction perpendicular to the substrate, and the color conversion light-emitting part comprises a second color light-emitting layer and a third color conversion layer stacked with the second color light-emitting layer in the first direction. The light-emitting efficiency of the third color in the display panel can be improved, and the brightness and the display effect of the display panel are improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a display panel and a display device. Background Art

[0002] Micro LED (Micro Light-Emitting Diode) display panels are micron-pitch LED arrays formed by miniaturizing traditional LEDs to achieve ultra-high density pixel resolution. Micro LED displays have the characteristics of self-luminescence. Compared with Organic Light-Emitting Diode (OLED) display panels and Liquid Crystal Display (LCD) display panels, the colors of Micro LED display panels are easier to accurately adjust, have longer luminous life and higher brightness, and are more lightweight and power-saving.

[0003] At present, in order to achieve other colors or full-color display of inorganic light-emitting diodes, it is often necessary to stack multiple inorganic light-emitting diodes together in a horizontal stack or a vertical stack, among which vertical stacking has the advantage of significantly improved PPI compared with horizontal stacking; however, due to the different luminous efficiencies of light-emitting layers of different colors, for example, the luminous efficiency of some colors is lower than that of other colors, it will affect the brightness and display effect of the display panel. Summary of the invention

[0004] Embodiments of the present invention provide a display panel and a display device, which can improve the luminous efficiency of a third color in the display panel and improve the brightness and display effect of the display panel.

[0005] An embodiment of the present invention further provides a display panel, the display panel comprising a substrate and at least one light emitting structure disposed on the substrate, the light emitting structure comprising:

[0006] A first light-emitting element, comprising a first color light-emitting layer;

[0007] A color conversion light-emitting element is stacked with the first light-emitting element on the substrate along a first direction, wherein the first direction is a direction perpendicular to the substrate, and the color conversion light-emitting element includes a second color light-emitting layer and a third color conversion layer stacked with the second color light-emitting layer along the first direction.

[0008] In one embodiment of the present invention, the luminous efficiency of the quantum well material of the third color is less than the luminous efficiency of the second color light-emitting layer, and the quantum well material of the third color includes at least one of InGaN, GaN, AlGaInP, and GaInP quantum well materials.

[0009] In one embodiment of the present invention, the luminous efficiency of the quantum well material of the third color is less than the luminous efficiency of the first color light-emitting layer.

[0010] In one embodiment of the present invention, the light-emitting structure also includes a second light-emitting element, and the second light-emitting element, the first light-emitting element, and the color conversion light-emitting element are stacked on the substrate along the first direction, the second light-emitting element includes a fourth color light-emitting layer, and the luminous efficiency of the third color quantum well material is less than the luminous efficiency of the fourth color light-emitting layer.

[0011] In one embodiment of the present invention, the color conversion light emitting element is arranged on the substrate, the second light emitting element is arranged on a side of the color conversion light emitting element away from the substrate, and the first light emitting element is arranged on a side of the second light emitting element away from the color conversion light emitting element;

[0012] The luminous efficiency of the first color luminous layer is greater than the luminous efficiency of the fourth color luminous layer.

[0013] In one embodiment of the present invention, the light emitting structure further comprises a first reflection layer disposed between the color conversion light emitting element and the substrate, and a second Bragg reflection layer disposed between the color conversion light emitting element and the second light emitting element;

[0014] The first reflection layer reflects the light of the second color and the light of the third color, and the second Bragg reflection layer reflects the light of the second color.

[0015] In an embodiment of the present invention, the first reflective layer includes a first Bragg reflective layer, the first Bragg reflective layer includes a first sub-portion and a second sub-portion stacked along the first direction, the first sub-portion reflects the light of the second color, and the second sub-portion reflects the light of the third color;

[0016] The first sub-section includes a plurality of first sub-layers and a plurality of second sub-layers stacked and alternately arranged, the second sub-section includes a plurality of third sub-layers and a plurality of fourth sub-layers stacked and alternately arranged, and the second Bragg reflection layer includes a plurality of fifth sub-layers and a plurality of sixth sub-layers stacked and alternately arranged;

[0017] Among them, the thickness of the first sublayer and the thickness of the second sublayer are both equal to one quarter of the wavelength of light of the second color, the thickness of the third sublayer and the thickness of the fourth sublayer are both equal to one quarter of the wavelength of light of the third color, and the thickness of the fifth sublayer and the thickness of the sixth sublayer are both equal to one quarter of the wavelength of light of the second color.

[0018] In one embodiment of the present invention, the material of the first sublayer, the material of the third sublayer and the material of the fifth sublayer all include silicon oxide materials, and the material of the second sublayer, the material of the fourth sublayer and the material of the sixth sublayer all include titanium oxide materials.

[0019] In one embodiment of the present invention, the display panel also includes at least one first electrode and a plurality of second electrodes connected to the light-emitting structure, at least the first color light-emitting layer and the fourth color light-emitting layer are both connected to the first electrode, and the first color light-emitting layer and the fourth color light-emitting layer are each independently connected to one of the second electrodes.

[0020] In one embodiment of the present invention, the first reflective layer is reused as a bonding metal layer, the color conversion light-emitting element is connected to the substrate through the bonding metal layer, and the second color light-emitting layer is connected to the first electrode, or to one of the second electrodes.

[0021] In an embodiment of the present invention, the first color is blue or green, the second color is blue or green, and the third color is red.

[0022] In one embodiment of the present invention, the fourth color is the same as or different from the second color.

[0023] In an embodiment of the present invention, the material of the third color conversion layer includes quantum dot material or phosphor material.

[0024] According to the above objective of the present invention, an embodiment of the present invention further provides a display device, which includes the display panel.

[0025] Beneficial effects of the present invention: In the present invention, a stacked second color light-emitting layer and a third color conversion layer are arranged in the color conversion light-emitting element, and then in the implementation and application process, the second color light-emitting layer with higher light-emitting efficiency can be selected to emit light to stimulate the third color conversion layer to emit light of the third color, so as to improve the light-emitting efficiency of the third color in the display panel, and improve the brightness and display effect of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0027] Figure 1 A schematic diagram of a light emitting structure provided by an embodiment of the present invention;

[0028] Figure 2 Another schematic diagram of the structure of the light emitting structure provided by an embodiment of the present invention;

[0029] Figure 3 Another schematic diagram of the structure of the light emitting structure provided by an embodiment of the present invention;

[0030] Figures 4 to 15 A structural schematic diagram of the manufacturing process of the light-emitting structure provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0033] The embodiment of the present invention further provides a display panel, please refer to Figure 1 The display panel includes a substrate 10 and at least one light emitting structure disposed on the substrate 10 , and the light emitting structure includes a first light emitting element 20 and a color conversion light emitting element 30 .

[0034] Among them, the first light-emitting element 20 includes a first color light-emitting layer 21; the color conversion light-emitting element 30 and the first light-emitting element 20 are stacked on the substrate 10 along a first direction M, and the first direction M is a direction perpendicular to the substrate 10. The color conversion light-emitting element 30 includes a second color light-emitting layer 31, and a third color conversion layer 32 stacked along the first direction M with the second color light-emitting layer 31.

[0035] During the implementation and application process, in the embodiment of the present invention, a stacked second color light-emitting layer 31 and a third color conversion layer 32 are arranged in the color conversion light-emitting element 30. The present invention can choose to use the second color light-emitting layer 31 with higher light-emitting efficiency to emit light to stimulate the third color conversion layer 32 to emit a third color of light, so as to improve the light-emitting efficiency of the third color in the display panel, thereby improving the brightness and display effect of the display panel.

[0036] Specifically, in one embodiment of the present invention, please continue to refer to Figure 1 The display panel includes a substrate 10 and a plurality of light emitting structures disposed on the substrate 10, and Figure 1 In the description, a light emitting structure disposed on the substrate 10 is taken as an example.

[0037] The light-emitting structure includes a color conversion light-emitting component 30, a second light-emitting component 40 and a first light-emitting component 20 which are stacked on a substrate 10 along a first direction M, and the first direction M is a direction perpendicular to the substrate 10, and the color conversion light-emitting component 30 is arranged on the substrate 10, the second light-emitting component 40 is arranged on a side of the color conversion light-emitting component 30 away from the substrate 10, and the first light-emitting component 20 is arranged on a side of the second light-emitting component 40 away from the color conversion light-emitting component 30.

[0038] Furthermore, the light-emitting structure may also include a bonding layer to bond the color-conversion light-emitting element 30, the second light-emitting element 40 and the first light-emitting element 20 to the substrate 10 along the first direction M; the light-emitting structure includes a first bonding layer 51 arranged between the substrate 10 and the color-conversion light-emitting element 30, a second bonding layer 52 arranged between the color-conversion light-emitting element 30 and the second light-emitting element 40, and a third bonding layer 53 arranged between the second light-emitting element 40 and the first light-emitting element 20; wherein, the color-conversion light-emitting element 30 is connected to the substrate 10 through the first bonding layer 51, the second light-emitting element 40 is connected to the side of the color-conversion light-emitting element 30 away from the substrate 10 through the second bonding layer 52, and the first light-emitting element 20 is connected to the side of the second light-emitting element 40 away from the color-conversion light-emitting element 30 through the third bonding layer 53.

[0039] In one embodiment, the first bonding layer 51 may include Au-Au bonding, Au-Sn bonding, Au-In bonding, Ti-Ti bonding and Cu-Cu bonding, and the thickness of the first bonding layer 51 may be greater than or equal to 0.1 microns and less than or equal to 3 microns. In addition to playing a bonding role, the first bonding layer 51 may also play a role in reflecting light, so that the light irradiated toward the substrate 10 in the light-emitting structure can be reflected back to improve the light extraction efficiency.

[0040] The materials of the second bonding layer 52 and the third bonding layer 53 may include transparent resin materials or silicon oxide materials, and the thickness of the second bonding layer 52 and the thickness of the third bonding layer 53 may both be greater than or equal to 0.1 microns and less than or equal to 5 microns, so that the second bonding layer 52 and the third bonding layer 53 can be transparent while playing a bonding role to avoid affecting the light output of the light-emitting structure.

[0041] In addition, the display panel also includes at least one first electrode 61 and a plurality of second electrodes 62 connected to the light-emitting structure, and the color conversion light-emitting element 30, the second light-emitting element 40 and the first light-emitting element 20 are all connected to the first electrode 61, and the color conversion light-emitting element 30, the second light-emitting element 40 and the first light-emitting element 20 are each independently connected to a second electrode 62; a circuit unit (not shown in the figure) is also provided in the substrate 10, and the first electrode 61 and the second electrode 62 are both connected to the circuit unit in the substrate 10 to realize signal transmission, so that the color conversion light-emitting element 30, the second light-emitting element 40 and the first light-emitting element 20 can emit light.

[0042] It should be noted that the display panel further includes an insulating layer 70 , and the insulating layer 70 covers the positions except for the positions where the first electrode 61 and the second electrode 62 are electrically connected to the light emitting structure.

[0043] In an embodiment of the present invention, the first light-emitting element 20 includes a first color light-emitting layer 21, and the first color light-emitting layer 21 may include a light-emitting layer and an N-type doped layer and a P-type doped layer located on both sides of the light-emitting layer, and one of the N-type doped layer and the P-type doped layer is connected to the first electrode 61, and the other is connected to the second electrode 62. For example, the first electrode 61 can be a P electrode and connected to the P-type doped layer, and the second electrode 62 can be an N electrode and connected to the N-type doped layer.

[0044] In one embodiment, the first color may be blue, and in the first color light-emitting layer 21, the n-type doped layer includes one or more of GaN, AlGaN, and AlInGaN, the material of the light-emitting layer includes InGaN / GaN quantum well material, and the P-type doped layer includes GaN material.

[0045] In one embodiment, in the first color light-emitting layer 21, a periodic stress adjustment layer and a current diffusion layer are further arranged between the N-type doped layer and the light-emitting layer, and a periodic stress adjustment layer and a current diffusion layer are further arranged between the P-type doped layer and the light-emitting layer, so as to enhance stress release and lateral current diffusion in the first color light-emitting layer 21 and improve the luminous efficiency of the first color light-emitting layer 21.

[0046] The second light-emitting element 40 includes a fourth color light-emitting layer 41, and the fourth color light-emitting layer 41 may include a light-emitting layer and an N-type doped layer and a P-type doped layer located on both sides of the light-emitting layer, and one of the N-type doped layer and the P-type doped layer is connected to the first electrode 61, and the other is connected to the second electrode 62. For example, the first electrode 61 can be a P electrode and connected to the P-type doped layer, and the second electrode 62 can be an N electrode and connected to the N-type doped layer.

[0047] In one embodiment, the fourth color may be green, and in the fourth color light-emitting layer 41, the n-type doped layer includes one or more of GaN, AlGaN, AlInGaN, the material of the light-emitting layer includes InGaN / GaN quantum well material, and the P-type doped layer includes GaN material.

[0048] In one embodiment, in the fourth color light-emitting layer 41, a periodic stress adjustment layer and a current diffusion layer are further arranged between the N-type doped layer and the light-emitting layer, and a periodic stress adjustment layer and a current diffusion layer are further arranged between the P-type doped layer and the light-emitting layer, so as to enhance stress release and lateral current diffusion in the fourth color light-emitting layer 41 and improve the luminous efficiency of the fourth color light-emitting layer 41.

[0049] The color conversion light-emitting element 30 includes a second color light-emitting layer 31 and a third color color conversion layer 32 stacked along a first direction M, and the third color color conversion layer 32 is arranged between the second color light-emitting layer 31 and the second light-emitting element 40, wherein the luminous efficiency of the quantum well material of the third color is less than the luminous efficiency of the second color light-emitting layer 31, that is, in the embodiment of the present invention, the second color light-emitting layer 31 with higher luminous efficiency is used to emit light to stimulate the third color color conversion layer 32 to emit light, thereby improving the luminous efficiency of the second color in the light-emitting structure, thereby improving the brightness and display effect of the display panel.

[0050] In one embodiment, the quantum well material of the third color includes at least one of InGaN, GaN, AlGaInP, and GaInP quantum well materials.

[0051] Furthermore, the luminous efficiency of the quantum well material of the third color can also be lower than the luminous efficiency of the first color luminous layer 21 and the luminous efficiency of the fourth color luminous layer 41, that is, in the embodiment of the present invention, by improving the light-emitting component with the lowest luminous efficiency in the light-emitting structure, the second color luminous layer 31 with higher luminous efficiency is used to emit light to stimulate the third color color conversion layer 32 to emit light, thereby improving the luminous efficiency of the third color in the light-emitting structure to improve the display effect of the display panel; in addition, the luminous efficiency of the first color luminous layer 21 is greater than the luminous efficiency of the fourth color luminous layer 41, and the first color luminous layer 21 is located above the fourth color luminous layer 41, thereby avoiding the first color light with stronger energy from exciting the fourth color luminous layer 41, so as to prevent the first color light from affecting the normal luminescence of the fourth color luminous layer 41.

[0052] In one embodiment, the color conversion light emitting element 30 is used to emit red light, that is, the third color is red, and the quantum well material of the third color can be AlGaInP / GaInP quantum well material; the third color color conversion layer 32 is used to excite red light, and the luminous efficiency of the blue quantum well material and the luminous efficiency of the green quantum well material are both greater than the luminous efficiency of the red quantum well material. Therefore, the second color can be blue or green to improve the luminous efficiency of red light in the light emitting structure. Figure 1 As shown, in this embodiment, the second color is blue as an example for description.

[0053] In one embodiment, the second color light emitting layer 31 may include a light emitting layer and an N-type doped layer and a P-type doped layer located on both sides of the light emitting layer, and one of the N-type doped layer and the P-type doped layer is connected to the first electrode 61, and the other is connected to the second electrode 62. For example, the first electrode 61 may be a P electrode and connected to the P-type doped layer, and the second electrode 62 may be an N electrode and connected to the N-type doped layer. In the second color light emitting layer 31, the n-type doped layer includes one or more of GaN, AlGaN, and AlInGaN, the material of the light emitting layer includes InGaN / GaN quantum well material, and the P-type doped layer includes GaN material.

[0054] In one embodiment, the material of the third color conversion layer 32 may include a phosphor material or a quantum dot material, for example, a red quantum dot material, and the red quantum dot material may be CdSe (cadmium selenide) or perovskite or InP (indium phosphide), and its half-peak width may be between 30nm and 50nm.

[0055] Further, in the embodiment of the present invention, the light emitting structure further includes a first reflective layer 33 disposed between the color conversion light emitting element 30 and the substrate 10, and a second Bragg reflective layer 34 disposed between the color conversion light emitting element 30 and the second light emitting element 40, wherein the first reflective layer 33 can reflect the light of the second color and the light of the third color, and the second Bragg reflective layer 34 can reflect the light of the second color. It can be understood that the first reflective layer 33 can reflect the light irradiated in the direction of the substrate 10 back to continue to participate in light conversion or light emission to improve the light emission efficiency, and the second Bragg reflective layer 34 can reflect the light of the second color with higher energy, such as blue light, back to prevent the light of the second color with higher energy from irradiating the second light emitting element 40 and exciting the fourth color light emitting layer 41, so as to prevent the light of the second color from affecting the normal light emission of the fourth color light emitting layer 41.

[0056] In one embodiment, the first reflective layer 33 may include a first Bragg reflective layer, and the first Bragg reflective layer may include a first sub-section and a second sub-section stacked along a first direction M, wherein the first sub-section may reflect light of a second color, and the second sub-section may reflect light of a third color, and the upper and lower positions of the first sub-section and the second sub-section may not be limited. The first sub-section includes a plurality of first sub-layers and a plurality of second sub-layers stacked and alternately arranged along the first direction M, that is, there is a second sub-layer between two adjacent first sub-layers, and there is a first sub-layer between two adjacent second sub-layers; the second sub-section includes a plurality of third sub-layers and a plurality of fourth sub-layers stacked and alternately arranged along the first direction M, that is, there is a fourth sub-layer between two adjacent third sub-layers, and there is a third sub-layer between two adjacent fourth sub-layers; the second Bragg reflective layer 34 includes a plurality of fifth sub-layers and a plurality of sixth sub-layers stacked and alternately arranged along the first direction M, that is, there is a sixth sub-layer between two adjacent fifth sub-layers, and there is a fifth sub-layer between two adjacent sixth sub-layers.

[0057] The materials of the first sublayer, the third sublayer and the fifth sublayer can all be silicon oxide materials, such as SiO2, and the materials of the second sublayer, the fourth sublayer and the sixth sublayer can all be titanium oxide materials, such as Ti2O3.

[0058] In one embodiment, the number of the first sub-layers, the number of the second sub-layers, the number of the third sub-layers, the number of the fourth sub-layers, the number of the fifth sub-layers, and the number of the sixth sub-layers can all be 15.

[0059] Furthermore, in the embodiment of the present invention, the thicknesses of the first sublayer, the second sublayer, the third sublayer, the fourth sublayer, the fifth sublayer and the sixth sublayer are designed so that the first Bragg reflection layer and the second Bragg reflection layer 34 can meet the purpose of reflecting light.

[0060] The first sub-portion can reflect light of the second color, the second sub-portion can reflect light of the third color, and the second Bragg reflection layer 34 can reflect light of the second color, wherein the thickness of the first sub-layer and the thickness of the second sub-layer are both equal to one quarter of the wavelength of the second color light. For example, when the second color is blue and the wavelength of the second color light is 455nm, the thickness of the first sub-layer and the thickness of the second sub-layer are both equal to 113.7nm.

[0061] The thickness of the third sublayer and the thickness of the fourth sublayer are both equal to one quarter of the wavelength of the third color light; for example, if the third color is red and the wavelength of the third color light is 630nm, the thickness of the third sublayer and the thickness of the fourth sublayer are both equal to 157.5nm.

[0062] The thickness of the fifth sublayer and the thickness of the sixth sublayer are both equal to one quarter of the wavelength of the second color light. For example, when the second color is blue and the wavelength of the second color light is 455nm, the thickness of the fifth sublayer and the thickness of the sixth sublayer are both equal to 113.7nm.

[0063] It should be noted that, in the embodiment of the present invention, a first reflective layer 33 and a second Bragg reflective layer 34 are respectively provided on opposite sides of the color conversion light-emitting element 30 to form a microcavity between the first reflective layer 33 and the second Bragg reflective layer 34, thereby filtering the light of the second color and further improving the light extraction efficiency of the third color light.

[0064] As mentioned above, in the embodiment of the present invention, a stacked second color light-emitting layer 31 and a third color conversion layer 32 are provided in the color conversion light-emitting element 30, and the luminous efficiency of the quantum well material of the third color is low, and is lower than the luminous efficiency of the second color light-emitting layer 31. That is, the present invention uses the second color light-emitting layer 31 with higher luminous efficiency to emit light to excite the third color conversion layer 32 to emit light of the third color, so as to improve the luminous efficiency of the third color in the display panel, thereby improving the brightness and display effect of the display panel.

[0065] In another embodiment of the present invention, please refer to Figure 2 , this embodiment and Figure 1 The difference between the illustrated embodiments is that the first reflective layer 33 is reused as a bonding metal layer, and the material of the first reflective layer 33 can be a conductive and reflective metal material, the color conversion light-emitting element 30 is connected to the substrate 10 through the bonding metal layer, and can be connected to the circuit unit (not shown in the figure) in the substrate 10 through the bonding metal layer.

[0066] The second light-emitting element 40 and the first light-emitting element 20 are both connected to the first electrode 61, and the second light-emitting element 40 and the first light-emitting element 20 are each independently connected to a second electrode 62, and the first electrode 61 and the second electrode 62 are both connected to the circuit unit in the substrate 10; the color conversion light-emitting element 30 is connected to the circuit unit in the substrate 10 through the bonding metal layer on the one hand, and on the other hand, the color conversion light-emitting element 30 is also connected to the first electrode 61, or connected to a second electrode 62, that is, the first reflective layer 33 is reused as the bonding metal layer, and can also be reused as the first electrode 61 or the second electrode 62; wherein, Figure 2 In the figure, the bonding metal layer is reused as the first electrode 61 as an example.

[0067] As mentioned above, while improving the luminous efficiency of the third color, this embodiment uses the first reflective layer 33 to be reused as a bonding metal layer and an electrode, thereby reducing the arrangement of the first electrode 61 or the second electrode 62 in the color conversion light-emitting element 30, and thus only needs to reserve a step on one side of the color conversion light-emitting element 30 to overlap the first electrode 61 or the second electrode 62, while the other side does not need to be etched to form a step, which can increase the luminous area of ​​the color conversion light-emitting element 30 and further improve the luminous efficiency of the third color in the display panel; correspondingly, since there is no need to reserve a step on one side of the color conversion light-emitting element 30, the second light-emitting element 40 and the first light-emitting element 20 corresponding to the side of the color conversion light-emitting element 30 where no step is reserved can also extend outward, which can also increase the luminous area of ​​the second light-emitting element 40 and the first light-emitting element 20 and improve the luminous efficiency of the second light-emitting element 40 and the first light-emitting element 20. Therefore, this embodiment is relative to Figure 1 In the illustrated embodiment, the luminous efficiency of the first light emitting element 20 , the color conversion light emitting element 30 and the second light emitting element 40 can be improved without increasing the area of ​​the light emitting structure, so as to reduce the power consumption of the display panel.

[0068] In another embodiment of the present invention, please refer to Figure 3 , this embodiment and Figure 1 The difference between the illustrated embodiment is that the light emitting structure includes a color conversion light emitting element 30 disposed on a substrate 10 and a first light emitting element 20 disposed on a side of the color conversion light emitting element 30 away from the substrate 10 .

[0069] In this embodiment, the color conversion luminescent element 30 includes a second color luminescent layer 31 and a third color conversion layer 32 stacked along the first direction M, and the luminous efficiency of the second color luminescent layer 31 is greater than the luminous efficiency of the third color quantum well material.

[0070] In one embodiment, the first color may be blue or green, the second color may also be blue or green, and the third color may be red. Since the luminous efficiency of the quantum well material that emits red light is low, in this embodiment, a second color light-emitting layer 31 with a higher luminous efficiency such as blue or green is used to emit light to stimulate the third color conversion layer 32 to emit red light, thereby improving the luminous efficiency of red light in the light-emitting structure and improving the brightness and display effect of the display panel.

[0071] In addition, the light emitting structure in this embodiment also includes a first reflective layer 33 disposed between the color conversion light emitting element 30 and the substrate 10, and a second Bragg reflective layer 34 disposed between the color conversion light emitting element 30 and the first light emitting element 20, and the structures of the first reflective layer 33 and the second Bragg reflective layer 34 in this embodiment can be the same as those in the embodiment of the present invention. Figure 1 The embodiments shown in are the same and will not be described again here.

[0072] As mentioned above, in the embodiment of the present invention, a stacked second color light-emitting layer 31 and a third color conversion layer 32 are provided in the color conversion light-emitting element 30, and the luminous efficiency of the quantum well material of the third color is low, and is lower than the luminous efficiency of the second color light-emitting layer 31. That is, the present invention uses the second color light-emitting layer 31 with higher luminous efficiency to emit light to excite the third color conversion layer 32 to emit light of the third color, so as to improve the luminous efficiency of the third color in the display panel, thereby improving the brightness and display effect of the display panel.

[0073] In other embodiments of the present invention, the second color may also be ultraviolet light, and the second color light-emitting layer 31 may also emit ultraviolet light, that is, ultraviolet light is used to excite the third color conversion layer 32 to emit a third color of light, such as red light.

[0074] In addition, the present invention also provides a method for manufacturing the display panel described in the above embodiment. Figure 1 , Figures 4 to 15 The manufacturing method of the display panel comprises the following steps:

[0075] First, a circuit unit is formed on a substrate 10 , and the circuit unit may include a pixel driver array.

[0076] Next, a second color light-emitting layer 31 is formed on the first sapphire substrate 81, wherein the second color may be blue, and the second color light-emitting layer 31 includes a light-emitting layer formed on the first sapphire substrate 81 and an N-type doped layer and a P-type doped layer located on opposite sides of the light-emitting layer; in one embodiment, the n-type doped layer includes one or more of GaN, AlGaN, and AlInGaN, the material of the light-emitting layer includes InGaN / GaN quantum well material, and the P-type doped layer includes GaN material.

[0077] Then, a first reflective layer 33 is formed on a side of the second color light emitting layer 31 away from the first sapphire substrate 81. The first reflective layer 33 includes a first Bragg reflective layer, such as Figure 4 As shown, the first Bragg reflective layer may include a first sub-section and a second sub-section stacked along a first direction M, wherein the first sub-section may reflect light of a second color, and the second sub-section may reflect light of a third color, and the upper and lower positions of the first sub-section and the second sub-section may not be limited. The first sub-section includes a plurality of first sub-layers and a plurality of second sub-layers stacked and alternately arranged along the first direction M, that is, there is a second sub-layer between two adjacent first sub-layers, and there is a first sub-layer between two adjacent second sub-layers; the second sub-section includes a plurality of third sub-layers and a plurality of fourth sub-layers stacked and alternately arranged along the first direction M, that is, there is a fourth sub-layer between two adjacent third sub-layers, and there is a third sub-layer between two adjacent fourth sub-layers.

[0078] The materials of the first sub-layer and the third sub-layer can both be silicon oxide materials, such as SiO2, and the materials of the second sub-layer and the fourth sub-layer can both be titanium oxide materials, such as Ti2O3.

[0079] In one embodiment, the number of the first sub-layers, the number of the second sub-layers, the number of the third sub-layers, and the number of the fourth sub-layers can all be 15.

[0080] Furthermore, the first sub-section can reflect light of a second color, and the second sub-section can reflect light of a third color, wherein the thickness of the first sub-layer and the thickness of the second sub-layer are both equal to one quarter of the wavelength of the second color light. For example, when the second color is blue and the wavelength of the second color light is 455nm, the thickness of the first sub-layer and the thickness of the second sub-layer are both equal to 113.7nm.

[0081] The thickness of the third sublayer and the thickness of the fourth sublayer are both equal to one quarter of the wavelength of the third color light; for example, if the third color is red and the wavelength of the third color light is 630nm, the thickness of the third sublayer and the thickness of the fourth sublayer are both equal to 157.5nm.

[0082] The first reflective layer 33 and the substrate 10 are connected together by using the first bonding layer 51, and the second color light emitting layer 31 is located on the side of the first reflective layer 33 away from the substrate 10, such as Figure 5 and Figure 6 shown.

[0083] In one embodiment, the first bonding layer 51 may include Au-Au bonding, Au-Sn bonding, Au-In bonding, Ti-Ti bonding and Cu-Cu bonding, and the thickness of the first bonding layer 51 may be greater than or equal to 0.1 microns and less than or equal to 3 microns. In addition to playing a bonding role, the first bonding layer 51 may also play a role of reflecting light, so that light irradiated toward the substrate 10 can be reflected back to improve the light extraction efficiency.

[0084] Then, the first sapphire substrate 81 may be removed by laser lift-off process or wet chemical etching, such as Figure 7 and Figure 8 shown.

[0085] Next, a third color conversion layer 32 and a second Bragg reflection layer 34 are sequentially formed on the side of the second color light emitting layer 31 away from the substrate 10, as shown in FIG. Figure 8 and Fig. 9 shown.

[0086] In one embodiment, the material of the third color conversion layer 32 may include a phosphor material or a quantum dot material, for example, a red quantum dot material, and the red quantum dot material may be CdSe (cadmium selenide) or perovskite or InP (indium phosphide), and its half-peak width may be between 30nm and 50nm.

[0087] In one embodiment, the second Bragg reflection layer 34 includes a plurality of fifth sublayers and a plurality of sixth sublayers stacked and alternately arranged along the first direction M, that is, one sixth sublayer is spaced between two adjacent fifth sublayers, and one fifth sublayer is spaced between two adjacent sixth sublayers.

[0088] The material of the fifth sub-layer may be a silicon oxide material, such as SiO2, and the material of the sixth sub-layer may be a titanium oxide material, such as Ti2O3, and the number of the fifth sub-layer and the sixth sub-layer may both be 15.

[0089] The second Bragg reflector 34 can reflect light of a second color. The thickness of the fifth sublayer and the thickness of the sixth sublayer are both equal to one quarter of the wavelength of the second color. For example, when the second color is blue and the wavelength of the second color is 455 nm, the thickness of the fifth sublayer and the thickness of the sixth sublayer are both equal to 113.7 nm.

[0090] Further, a second light-emitting element 40 is formed on the second sapphire substrate 82, and the second light-emitting element 40 includes a fourth color light-emitting layer 41 formed on the second sapphire substrate 82. In one embodiment, the fourth color may be green, and the fourth color light-emitting layer 41 may include a light-emitting layer and an N-type doping layer and a P-type doping layer located on opposite sides of the light-emitting layer, in the fourth color light-emitting layer 41, the n-type doping layer includes one or more of GaN, AlGaN, and AlInGaN, the material of the light-emitting layer includes InGaN / GaN quantum well material, and the P-type doping layer includes GaN material.

[0091] In one embodiment, in the fourth color light-emitting layer 41, a periodic stress adjustment layer and a current diffusion layer are further arranged between the N-type doped layer and the light-emitting layer, and a periodic stress adjustment layer and a current diffusion layer are further arranged between the P-type doped layer and the light-emitting layer, so as to enhance stress release and lateral current diffusion in the fourth color light-emitting layer 41 and improve the luminous efficiency of the fourth color light-emitting layer 41.

[0092] Next, the fourth color light emitting layer 41 is connected to the side of the second Bragg reflection layer 34 away from the substrate 10 through the second bonding layer 52, as shown in FIG. Fig.10 and Fig.11 shown.

[0093] In one embodiment, the material of the second bonding layer 52 may include a transparent resin material or a silicon oxide material, and the thickness of the second bonding layer 52 may be greater than or equal to 0.1 microns and less than or equal to 5 microns, so that the second bonding layer 52 can be transparent while playing a bonding role to avoid affecting the light output of the light-emitting structure.

[0094] Then, the second sapphire substrate 82 may be removed by laser lift-off or wet chemical etching. Fig.12 shown.

[0095] Next, a first light emitting element 20 is formed on the third sapphire substrate 83, and the first light emitting element 20 includes a first color light emitting layer 21 formed on the third sapphire substrate 83, as shown in FIG. Fig.13 shown.

[0096] In one embodiment, the first color may be blue, and the first color light-emitting layer 21 may include a light-emitting layer and an N-type doped layer and a P-type doped layer located on opposite sides of the light-emitting layer. In the first color light-emitting layer 21, the n-type doped layer includes one or more of GaN, AlGaN, and AlInGaN, the material of the light-emitting layer includes InGaN / GaN quantum well material, and the P-type doped layer includes GaN material.

[0097] In one embodiment, in the first color light-emitting layer 21, a periodic stress adjustment layer and a current diffusion layer are further arranged between the N-type doped layer and the light-emitting layer, and a periodic stress adjustment layer and a current diffusion layer are further arranged between the P-type doped layer and the light-emitting layer, so as to enhance stress release and lateral current diffusion in the first color light-emitting layer 21 and improve the luminous efficiency of the first color light-emitting layer 21.

[0098] Furthermore, the first color light emitting layer 21 is connected to the side of the fourth color light emitting layer 41 away from the substrate 10 through the third bonding layer 53, as shown in FIG. Fig.14 shown.

[0099] In one embodiment, the material of the third bonding layer 53 may include a transparent resin material or a silicon oxide material, and the thickness of the third bonding layer 53 may be greater than or equal to 0.1 microns and less than or equal to 5 microns, so that the third bonding layer 53 can be transparent while playing a bonding role to avoid affecting the light output of the light-emitting structure.

[0100] Furthermore, the third sapphire substrate 83 may be removed by laser lift-off or wet chemical etching. Fig.15 shown.

[0101] Finally, Fig.14The stacked structure after removing the third sapphire substrate 83 is patterned, that is, the color conversion light-emitting element 30, the second light-emitting element 40 and the first light-emitting element 20 are patterned to form a stepped side to accommodate the electrode; then, at least one first electrode 61 and a plurality of second electrodes 62 are formed, such as Figure 1 shown.

[0102] Among them, in the first color light-emitting layer 21, one of the N-type doped layer and the P-type doped layer is connected to the first electrode 61, and the other is connected to the second electrode 62. For example, the first electrode 61 can be a P electrode and connected to the P-type doped layer, and the second electrode 62 can be an N electrode and connected to the N-type doped layer.

[0103] In the fourth color light-emitting layer 41, one of the N-type doped layer and the P-type doped layer is connected to the first electrode 61, and the other is connected to the second electrode 62. For example, the first electrode 61 can be a P electrode and connected to the P-type doped layer, and the second electrode 62 can be an N electrode and connected to the N-type doped layer.

[0104] In the second color light-emitting layer 31, one of the N-type doped layer and the P-type doped layer is connected to the first electrode 61, and the other is connected to the second electrode 62. For example, the first electrode 61 can be a P electrode and connected to the P-type doped layer, and the second electrode 62 can be an N electrode and connected to the N-type doped layer.

[0105] As mentioned above, in the embodiment of the present invention, a stacked second color light-emitting layer 31 and a third color conversion layer 32 are provided in the color conversion light-emitting element 30, and the luminous efficiency of the quantum well material of the third color is low, and is lower than the luminous efficiency of the second color light-emitting layer 31. That is, the present invention uses the second color light-emitting layer 31 with higher luminous efficiency to emit light to excite the third color conversion layer 32 to emit light of the third color, so as to improve the luminous efficiency of the third color in the display panel, thereby improving the brightness and display effect of the display panel.

[0106] In addition, an embodiment of the present invention further provides a display device, which includes the display panel described in the above embodiment.

[0107] The display device may include a television, a computer, a mobile phone, a tablet, a VR or AR display device, etc.

[0108] A display device provided by an embodiment of the present invention has the same beneficial effects as the above-mentioned display panel because it is provided with the display panel provided by the above-mentioned embodiment of the present invention.

[0109] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0110] A display panel and a display device provided by an embodiment of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present invention. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A display panel, characterized in that: The display panel includes a substrate and at least one light emitting structure disposed on the substrate, wherein the light emitting structure includes: A first light-emitting element, comprising a first color light-emitting layer; A color conversion light-emitting element is stacked with the first light-emitting element on the substrate along a first direction, wherein the first direction is a direction perpendicular to the substrate, and the color conversion light-emitting element includes a second color light-emitting layer and a third color conversion layer stacked with the second color light-emitting layer along the first direction.

2. The display panel according to claim 1, characterized in that: The luminous efficiency of the third color quantum well material is lower than that of the second color light-emitting layer, and the third color quantum well material includes at least one of InGaN, GaN, AlGaInP, and GaInP quantum well materials.

3. The display panel according to claim 1, characterized in that: The luminous efficiency of the quantum well material of the third color is lower than the luminous efficiency of the first color light-emitting layer.

4. The display panel according to claim 1, characterized in that: The light-emitting structure also includes a second light-emitting component, which is stacked on the substrate along the first direction with the first light-emitting component and the color conversion light-emitting component. The second light-emitting component includes a fourth color light-emitting layer, and the light-emitting efficiency of the third color quantum well material is less than the light-emitting efficiency of the fourth color light-emitting layer.

5. The display panel according to claim 4, characterized in that: The color conversion light emitting element is arranged on the substrate, the second light emitting element is arranged on a side of the color conversion light emitting element away from the substrate, and the first light emitting element is arranged on a side of the second light emitting element away from the color conversion light emitting element; The luminous efficiency of the first color luminous layer is greater than the luminous efficiency of the fourth color luminous layer.

6. The display panel according to claim 5, characterized in that: The light emitting structure further comprises a first reflection layer disposed between the color conversion light emitting element and the substrate, and a second Bragg reflection layer disposed between the color conversion light emitting element and the second light emitting element; The first reflection layer reflects the light of the second color and the light of the third color, and the second Bragg reflection layer reflects the light of the second color.

7. The display panel according to claim 6, characterized in that: The first reflective layer includes a first Bragg reflective layer, the first Bragg reflective layer includes a first sub-portion and a second sub-portion stacked along the first direction, the first sub-portion reflects the light of the second color, and the second sub-portion reflects the light of the third color; The first sub-section includes a plurality of first sub-layers and a plurality of second sub-layers stacked and alternately arranged, the second sub-section includes a plurality of third sub-layers and a plurality of fourth sub-layers stacked and alternately arranged, and the second Bragg reflection layer includes a plurality of fifth sub-layers and a plurality of sixth sub-layers stacked and alternately arranged; Among them, the thickness of the first sublayer and the thickness of the second sublayer are both equal to one quarter of the wavelength of light of the second color, the thickness of the third sublayer and the thickness of the fourth sublayer are both equal to one quarter of the wavelength of light of the third color, and the thickness of the fifth sublayer and the thickness of the sixth sublayer are both equal to one quarter of the wavelength of light of the second color.

8. The display panel according to claim 7, characterized in that: The material of the first sublayer, the material of the third sublayer and the material of the fifth sublayer all include silicon oxide materials, and the material of the second sublayer, the material of the fourth sublayer and the material of the sixth sublayer all include titanium oxide materials.

9. The display panel according to claim 6, characterized in that: The display panel also includes at least one first electrode and multiple second electrodes connected to the light-emitting structure, at least the first color light-emitting layer and the fourth color light-emitting layer are both connected to the first electrode, and the first color light-emitting layer and the fourth color light-emitting layer are each independently connected to one of the second electrodes.

10. The display panel according to claim 9, characterized in that: The first reflective layer is reused as a bonding metal layer, the color conversion light-emitting element is connected to the substrate through the bonding metal layer, and the second color light-emitting layer is connected to the first electrode, or is connected to one of the second electrodes.

11. The display panel according to claim 4, characterized in that: The first color is blue or green, the second color is blue or green, and the third color is red.

12. The display panel according to claim 11, characterized in that: The fourth color is the same as or different from the second color.

13. The display panel according to claim 1, characterized in that: The material of the third color conversion layer includes quantum dot material or phosphor material.

14. A display device, characterized in that: The display device comprises the display panel according to any one of claims 1 to 13.

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