Light emitting device and display substrate

Abstract

The present invention relates to a light emitting device and a display substrate. The light emitting device comprises: a first light emitting structure, a first electrode, a first conductive structure and a first reflective layer; the first electrode is electrically connected to the first light emitting structure through the first conductive structure, the first reflective layer is located between the first electrode and the first light emitting structure, and the projection of the first electrode on the first light emitting structure is located within the projection of the first reflective layer on the first light emitting structure. According to the embodiments of the present invention, the light emitting efficiency of the light emitting device can be improved.

Description

Technical Field

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

[0002] In the related art, the luminous efficiency of light emitting diodes (LEDs) is relatively low. Therefore, how to improve the luminous efficiency of LEDs is a technical problem that needs to be solved. Summary of the invention

[0003] The present invention provides a light emitting device and a display substrate to solve the deficiencies in the related art.

[0004] According to a first aspect of an embodiment of the present invention, there is provided a light emitting device, comprising: a first light emitting structure, a first electrode, a first conductive structure and a first reflective layer;

[0005] The first electrode is electrically connected to the first light-emitting structure through the first conductive structure, the first reflective layer is located between the first electrode and the first light-emitting structure, and the projection of the first electrode on the first light-emitting structure is located within the projection of the first reflective layer on the first light-emitting structure.

[0006] In one embodiment, the material of the first reflective layer is an insulating material; the first reflective layer is a Bragg reflector;

[0007] The first reflective layer is located in the first conductive structure, and the first conductive structure is in contact with the first light-emitting structure.

[0008] In one embodiment, the first conductive structure includes a first conductive layer and a second conductive layer, the first conductive layer is located on the first light-emitting structure and is electrically connected to the first light-emitting structure, the first reflective layer is located on a side of the first conductive layer away from the first light-emitting structure, and a projection of the first reflective layer on the first light-emitting structure is located within a projection of the first conductive layer on the first light-emitting structure, the second conductive layer is located on a side of the first reflective layer away from the first conductive layer, and a projection of the first reflective layer on the first light-emitting structure is located within a projection of the second conductive layer on the first light-emitting structure; and the second conductive layer overlaps the first conductive layer.

[0009] In one embodiment, the first light emitting structure includes a first semiconductor layer, a first light emitting layer and a second semiconductor layer, the first light emitting layer is located between the first semiconductor layer and the second semiconductor layer, and the first electrode is electrically connected to the second semiconductor layer.

[0010] In one embodiment, the surface of the second semiconductor layer away from the first light emitting layer includes a first region and a second region, and the first region is adjacent to the second region;

[0011] The first conductive layer is located on a side of the second semiconductor layer away from the first light-emitting layer, and a contact surface between the first conductive layer and the second semiconductor layer is located in the first region; the second conductive layer covers the first reflective layer, the first conductive layer and the second semiconductor layer, and a contact surface between the second conductive layer and the second semiconductor layer is located in the second region; a projection of the first reflective layer on the second semiconductor layer is located in the first region.

[0012] In one embodiment, the sum of the area of ​​the contact surface between the first conductive layer and the second semiconductor layer and the area of ​​the contact surface between the second conductive layer and the second semiconductor layer is less than or equal to the area of ​​the surface of the second semiconductor layer away from the first light emitting layer.

[0013] In one embodiment, the first conductive layer is located on a side of the second semiconductor layer away from the first light emitting layer, and covers part or all of the second semiconductor layer;

[0014] The second conductive layer covers the first reflective layer and the first conductive layer, and a projection of the second conductive layer on the second semiconductor layer is located within a projection of the first conductive layer on the second semiconductor layer.

[0015] In one embodiment, the light emitting device further includes a second light emitting structure, a second electrode, a second conductive structure and a second reflective layer;

[0016] The second light emitting structure and the first light emitting structure are connected in series via the second electrode and the second conductive structure;

[0017] The first end of the second electrode is electrically connected to the second light emitting structure through the second conductive structure, and the second end of the second electrode is electrically connected to the first light emitting structure;

[0018] The second reflective layer is located between the second electrode and the second light emitting structure, and a projection of the second electrode on the second light emitting structure is located within a projection of the second reflective layer on the second light emitting structure.

[0019] In one embodiment, the material of the second reflective layer is an insulating material; the second reflective layer is a Bragg reflector;

[0020] The second reflective layer is located in the second conductive structure, and the second conductive structure is in contact with the second light emitting structure.

[0021] In one embodiment, the second light emitting structure includes a third semiconductor layer, a second light emitting layer and a fourth semiconductor layer, the second light emitting layer is located between the third semiconductor layer and the fourth semiconductor layer, and the second electrode is electrically connected to the fourth semiconductor layer;

[0022] The second conductive structure includes a third conductive layer and a fourth conductive layer, the third conductive layer is located on a side of the fourth semiconductor layer away from the second light-emitting layer, the second reflective layer is located on a side of the third conductive layer away from the fourth semiconductor layer, a projection of the second reflective layer on the fourth semiconductor layer is located within a projection of the third conductive layer on the fourth semiconductor layer, the fourth conductive layer is located on a side of the second reflective layer away from the third conductive layer, and a projection of the second reflective layer on the fourth semiconductor layer is located within a projection of the fourth conductive layer on the fourth semiconductor layer; the fourth conductive layer overlaps the third conductive layer; and the first end of the second electrode is located on a side of the fourth conductive layer away from the fourth semiconductor layer.

[0023] In one embodiment, a surface of the fourth semiconductor layer away from the second light emitting layer includes a third region and a fourth region, and the third region is adjacent to the fourth region;

[0024] The contact surface between the third conductive layer and the fourth semiconductor layer is located in the third region; the fourth conductive layer covers part of the second reflective layer, part of the third conductive layer and part of the fourth semiconductor layer, and the contact surface between the fourth conductive layer and the fourth semiconductor layer is located in the fourth region; the projection of the second reflective layer on the fourth semiconductor layer is located in the third region;

[0025] The sum of the area of ​​the contact surface between the third conductive layer and the fourth semiconductor layer and the area of ​​the contact surface between the fourth conductive layer and the fourth semiconductor layer is less than or equal to the area of ​​the surface of the fourth semiconductor layer away from the second light emitting layer.

[0026] In one embodiment, the third conductive layer covers part or all of the fourth semiconductor layer;

[0027] The fourth conductive layer covers the second reflective layer and the third conductive layer, and a projection of the fourth conductive layer on the fourth semiconductor layer is located within a projection of the third conductive layer on the fourth semiconductor layer.

[0028] According to a second aspect of an embodiment of the present invention, there is provided a display substrate, comprising: a driving backplane and the above-mentioned light-emitting device;

[0029] The light emitting device is electrically connected to the driving backplane.

[0030] According to the above embodiments, since the first reflective layer is located between the first electrode and the first light-emitting structure, the first reflective layer can reflect the light emitted by the first light-emitting structure toward the first electrode back, thereby preventing the first electrode from absorbing the light emitted by the first light-emitting structure, thereby improving the light-emitting efficiency of the light-emitting device.

[0031] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0033] Figure 1 is a schematic structural diagram of a light emitting device according to an embodiment of the present invention;

[0034] Figure 2 is a schematic structural diagram of another light emitting device according to an embodiment of the present invention;

[0035] Figure 3 is a schematic diagram showing the relationship between current density and luminous efficiency according to an embodiment of the present invention;

[0036] Figure 4 is a schematic structural diagram of another light emitting device according to an embodiment of the present invention;

[0037] Figure 5 FIG. 4 is a schematic structural diagram of another light emitting device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0039] The embodiment of the present invention provides a light emitting device. The light emitting device, such as Figure 1 As shown, it includes: a first light emitting structure 11 , a first electrode 12 , a first conductive structure 13 and a first reflective layer 14 .

[0040] The first electrode 12 is electrically connected to the first light emitting structure 11 through the first conductive structure 13 . The first reflective layer 14 is located between the first electrode 12 and the first light emitting structure 11 . The projection of the first electrode 12 on the first light emitting structure 11 is located within the projection of the first reflective layer 14 on the first light emitting structure 11 .

[0041] In this embodiment, since the first reflective layer 14 is located between the first electrode 12 and the first light-emitting structure 11, the first reflective layer 14 can reflect the light emitted by the first light-emitting structure 11 toward the first electrode 12 back, thereby preventing the first electrode 12 from absorbing the light emitted by the first light-emitting structure 11, thereby improving the light-emitting efficiency of the light-emitting device.

[0042] The light emitting device provided by the embodiment of the present invention is briefly introduced above. The light emitting device provided by the embodiment of the present invention is introduced in detail below.

[0043] The embodiment of the present invention further provides a light emitting device. The light emitting device, such as Figure 1 As shown, it includes: a substrate 15, a first light emitting structure 11, a first electrode 12, a first conductive structure 13, a first reflective layer 14, a second light emitting structure 16, a second electrode 17, a second conductive structure 18, a second reflective layer 19, a third electrode 21, a first insulating layer 22, a second insulating layer 23, a third reflective layer 24, a first conductive portion 25 and a second conductive portion 26.

[0044] In the present embodiment, the light emitting device may be a high voltage LED (light emitting diode), but is not limited thereto.

[0045] In this embodiment, the material of the substrate 15 is sapphire. The main component of sapphire is aluminum oxide (Al2O3). Of course, in other embodiments, the material of the substrate 15 can also be silicon carbide (SiC), gallium nitride (GaN) or silicon.

[0046] In this embodiment, if Figure 1 As shown, the first light emitting structure 11 is located on the substrate 15. The first light emitting structure 11 includes a first semiconductor layer 111, a first superlattice layer 112, a first semiconductor layer 113, a first light emitting layer 114, a first electron blocking layer 115 and a second semiconductor layer 116. Among them, the first semiconductor layer 111 and the first semiconductor layer 113 are one of a P-type semiconductor layer and an N-type semiconductor layer, and the second semiconductor layer 116 is the other of a P-type semiconductor layer and an N-type semiconductor layer. In this embodiment, the first semiconductor layer 111 and the first semiconductor layer 113 are N-type semiconductor layers, and the second semiconductor layer 116 is a P-type semiconductor layer.

[0047] In this embodiment, if Figure 1As shown, the first semiconductor layer 111 is located on the substrate 15, the first superlattice layer 112 is located on the side of the first semiconductor layer 111 away from the substrate 15, and the first semiconductor layer 113 is located on the side of the first superlattice layer 112 away from the first semiconductor layer 111. The material of the first superlattice layer 112 can be GaN or InGaN, but is not limited thereto. The first superlattice layer 112 is configured to improve the lattice matching between the first semiconductor layer 111 and the first semiconductor layer 113, and reduce or prevent defects from propagating from the substrate 15 and the first semiconductor layer 111 to the first semiconductor layer 113, so as to avoid functional disorders of the light-emitting device.

[0048] In this embodiment, the first light emitting layer 114 is located on a side of the first semiconductor layer 113 away from the substrate 15. The first light emitting layer 114 may include a multi-quantum well structure. For example, the multi-quantum well structure may be a periodic structure in which GaN (gallium nitride) and InGaN (indium gallium nitride) are alternately arranged, but is not limited thereto.

[0049] In this embodiment, if Figure 1 As shown, the first electron blocking layer 115 is located on a side of the first light emitting layer 114 away from the first semiconductor layer 113, and the second semiconductor layer 116 is located on a side of the first light emitting layer 114 away from the first semiconductor layer 113. The first electron blocking layer 115 is configured to prevent electrons in the first light emitting layer 114 from escaping to the second semiconductor layer 116, which can improve the light emitting efficiency.

[0050] In this embodiment, if Figure 1 As shown, the second light emitting structure 16 is also located on the substrate 15. The first light emitting structure 11 and the second light emitting structure 16 can be located side by side on the substrate 15. The second light emitting structure 16 includes a third semiconductor layer 161, a second superlattice layer 162, a third semiconductor layer 163, a second light emitting layer 164, a second electron blocking layer 165 and a fourth semiconductor layer 166. Among them, the third semiconductor layer 161 and the third semiconductor layer 163 are one of a P-type semiconductor layer and an N-type semiconductor layer, and the fourth semiconductor layer 166 is the other of a P-type semiconductor layer and an N-type semiconductor layer. In this embodiment, the third semiconductor layer 161 and the third semiconductor layer 163 are N-type semiconductor layers, and the fourth semiconductor layer 166 is a P-type semiconductor layer. For example, the third semiconductor layer 161 and the third semiconductor layer 163 are N-type semiconductor layers, and the fourth semiconductor layer 166 is a P-type semiconductor layer.

[0051] In this embodiment, if Figure 1As shown, the third semiconductor layer 161 is located on the substrate 15, the second superlattice layer 162 is located on the side of the third semiconductor layer 161 away from the substrate 15, and the third semiconductor layer 163 is located on the side of the second superlattice layer 162 away from the third semiconductor layer 161. The material of the second superlattice layer 162 can be GaN or InGaN, but is not limited thereto. The second superlattice layer 162 is configured to improve the lattice matching between the third semiconductor layer 161 and the third semiconductor layer 163, and reduce or prevent defects from propagating from the substrate 15 and the third semiconductor layer 161 to the third semiconductor layer 163, so as to avoid functional disorders of the light-emitting device.

[0052] In this embodiment, the second light emitting layer 164 is located on a side of the third semiconductor layer 163 away from the substrate 15. The second light emitting layer 164 may include a multi-quantum well structure. For example, the multi-quantum well structure may be a periodic structure in which GaN (gallium nitride) and InGaN (indium gallium nitride) are alternately arranged, but is not limited thereto.

[0053] In this embodiment, if Figure 1 As shown, the second electron blocking layer 165 is located on a side of the second light emitting layer 164 away from the third semiconductor layer 163, and the fourth semiconductor layer 166 is located on a side of the second light emitting layer 164 away from the third semiconductor layer 163. The second electron blocking layer 165 is configured to prevent electrons in the second light emitting layer 164 from escaping to the fourth semiconductor layer 166, which can improve the light emission efficiency.

[0054] In this embodiment, if Figure 1 As shown, the first conductive structure 13 is located on a side of the first light emitting structure 11 away from the substrate 15, and is in contact with the first light emitting structure 11. The first conductive structure 13 is located on a side of the second semiconductor layer 116 away from the substrate 15, and is in contact with the second semiconductor layer 116. The material of the first conductive structure 13 may be a transparent conductive material, such as ITO (indium tin oxide), but is not limited thereto.

[0055] In this embodiment, the first reflective layer 14 is a Bragg reflector with a relatively high reflectivity. The first reflective layer 14 can be formed by alternating high refractive index materials and low refractive index materials. For example, the first reflective layer 14 can include multiple layers of SiO2 and TiO2 alternately arranged, but is not limited thereto. The thickness of each layer of high refractive index material and the thickness of each layer of low refractive index material are both one-quarter of the central reflection wavelength. The number of layers of high refractive index material is the same as the number of layers of low refractive index material.

[0056] In this embodiment, if Figure 1As shown, the material of the first reflective layer 14 is an insulating material, and the first reflective layer 14 is located in the first conductive structure 13. In this way, the first reflective layer 14 does not affect the electrical connection between the first electrode 12 and the first light-emitting structure 11 through the first conductive structure 13. In other embodiments, the material of the first reflective layer 14 may be a conductive material with a higher reflectivity, such as silver or aluminum.

[0057] In this embodiment, if Figure 1 As shown, the first conductive structure 13 includes a first conductive layer 131 and a second conductive layer 132. The first conductive layer 131 is located on the second semiconductor layer 116 of the first light emitting structure 11 and is electrically connected to the second semiconductor layer 116. The first reflective layer 14 is located on a side of the first conductive layer 131 away from the first light emitting structure 11. The projection of the first reflective layer 14 on the first light emitting structure 11 is located within the projection of the first conductive layer 131 on the first light emitting structure 11. The second conductive layer 132 is located on a side of the first reflective layer 14 away from the first conductive layer 131. The projection of the first reflective layer 14 on the first light emitting structure 11 is located within the projection of the second conductive layer 132 on the first light emitting structure 11. The material of the first conductive layer 131 and the material of the second conductive layer 132 may be ITO (indium tin oxide), but is not limited thereto.

[0058] In this embodiment, if Figure 1 As shown, the surface of the second semiconductor layer 116 away from the first light emitting layer 114 includes a first region Q1 and a second region Q2, and the first region Q1 is adjacent to the second region Q2. The first conductive layer 131 is located on the side of the second semiconductor layer 116 away from the first light emitting layer 114, and the contact surface between the first conductive layer 131 and the second semiconductor layer 116 is located in the first region Q1. The second conductive layer 132 covers the first reflective layer 14, the first conductive layer 131 and the second semiconductor layer 116, and the contact surface between the second conductive layer 132 and the second semiconductor layer 116 is located in the second region Q2. The projection of the first reflective layer 14 on the second semiconductor layer 116 is located in the first region Q1. The second conductive layer 132 overlaps the first conductive layer 131 on the side of the first conductive layer 131 close to the second light emitting structure 16.

[0059] In this embodiment, if Figure 1 As shown, the sum of the area of ​​the contact surface between the first conductive layer 131 and the second semiconductor layer 116 and the area of ​​the contact surface between the second conductive layer 132 and the second semiconductor layer 116 is substantially equal to the area of ​​the surface of the second semiconductor layer 116 away from the first light-emitting layer 114. The meaning of "substantially equal to" includes "equal to" and "approximately equal to". That is, the surface of the second semiconductor layer 116 away from the first light-emitting layer 114 is substantially covered by the first conductive structure 13. Among them, the area of ​​the part of the surface of the second semiconductor layer 116 away from the first light-emitting layer 114 covered by the first conductive structure 13 is the light-emitting area of ​​the first light-emitting structure.

[0060] In this embodiment, if Figure 1 As shown, the first electrode 12 is a positive electrode. The first electrode 12 is located on a side of the first conductive structure 13 away from the substrate 15. The first electrode 12 is in contact with the first conductive structure 13, and the first electrode 12 is electrically connected to the first conductive structure 13.

[0061] In this embodiment, if Figure 1 As shown, the first reflective layer 14 is located between the first electrode 12 and the first light emitting structure 11 , and the projection of the first electrode 12 on the first light emitting structure 11 is located within the projection of the first reflective layer 14 on the first light emitting structure 11 .

[0062] In this embodiment, since the first reflective layer 14 is located between the first electrode 12 and the first light-emitting structure 11, the first reflective layer 14 can reflect the light emitted by the first light-emitting structure 11 toward the first electrode 12 back, thereby preventing the first electrode 12 from absorbing the light emitted by the first light-emitting structure 11, thereby improving the light-emitting efficiency of the light-emitting device.

[0063] In this embodiment, if Figure 1 As shown, the first light emitting structure 11 and the second light emitting structure 16 are connected in series via the second electrode 17 and the second conductive structure 18. The light emitting color of the first light emitting structure 11 and the light emitting color of the second light emitting structure 16 may be the same.

[0064] In this embodiment, if Figure 1 As shown, the second conductive structure 18 is located on a side of the second light emitting structure 16 away from the substrate 15, and is electrically connected to the second light emitting structure 16. The second conductive structure 18 is located on a side of the fourth semiconductor layer 166 away from the substrate 15, and is in contact with the fourth semiconductor layer 166. The second conductive structure 18 is electrically connected to the fourth semiconductor layer 166. The material of the second conductive structure 18 may be a transparent conductive material, such as ITO (indium tin oxide), but is not limited thereto.

[0065] In this embodiment, the second reflective layer 19 is a Bragg reflector. The second reflective layer 19 may be formed by alternating high refractive index materials and low refractive index materials. For example, the second reflective layer 19 may include multiple layers of SiO2 and TiO2 alternately arranged, but is not limited thereto. The thickness of each layer of high refractive index material and the thickness of each layer of low refractive index material are both one-quarter of the central reflection wavelength. The number of layers of high refractive index material is the same as the number of layers of low refractive index material.

[0066] In this embodiment, if Figure 1 As shown, the material of the second reflective layer 19 is an insulating material, and the second reflective layer 19 is located in the second conductive structure 18. In this way, the second reflective layer 19 does not affect the electrical connection between the second electrode 17 and the second light emitting structure 16 through the second conductive structure 18.

[0067] In this embodiment, if Figure 1 As shown, the second conductive structure 18 includes a third conductive layer 181 and a fourth conductive layer 182. The third conductive layer 181 is located on a side of the fourth semiconductor layer 166 away from the second light emitting layer 164, the second reflective layer 19 is located on a side of the third conductive layer 181 away from the fourth semiconductor layer 166, the projection of the second reflective layer 19 on the fourth semiconductor layer 166 is located within the projection of the third conductive layer 181 on the fourth semiconductor layer 166, the fourth conductive layer 182 is located on a side of the second reflective layer 19 away from the third conductive layer 181, and the projection of the second reflective layer 19 on the fourth semiconductor layer 166 is located within the projection of the fourth conductive layer 182 on the fourth semiconductor layer 166. The first end S1 of the second electrode 17 is located on a side of the fourth conductive layer 182 away from the fourth semiconductor layer 166. The material of the third conductive layer 181 and the material of the fourth conductive layer 182 may be ITO (indium tin oxide), but is not limited thereto.

[0068] In this embodiment, if Figure 1 As shown, the surface of the fourth semiconductor layer 166 away from the second light emitting layer 164 includes a third region Q3 and a fourth region Q4, and the third region Q3 is adjacent to the fourth region Q4. The third region Q3 is located on the side of the fourth semiconductor layer 166 close to the first light emitting structure. The contact surface between the third conductive layer 181 and the fourth semiconductor layer 166 is located in the third region Q3. The fourth conductive layer 182 may cover part of the second reflective layer 19, part of the third conductive layer 181, and part of the fourth semiconductor layer 166. For example, the fourth conductive layer 182 does not cover the side of the second reflective layer 19 close to the first light emitting structure 11, the side of the third conductive layer 181 close to the first light emitting structure 11, and the side of the fourth semiconductor layer 166 close to the first light emitting structure 11. The contact surface between the fourth conductive layer 182 and the fourth semiconductor layer 166 is located in the fourth region Q4. The projection of the second reflective layer 19 on the fourth semiconductor layer 166 is located in the third region Q3. The fourth conductive layer 182 overlaps the third conductive layer 181 on the side of the third conductive layer 181 away from the first light emitting structure 11.

[0069] In this embodiment, if Figure 1 As shown, the sum of the contact surface area between the third conductive layer 181 and the fourth semiconductor layer 166 and the contact surface area between the fourth conductive layer 182 and the fourth semiconductor layer 166 is substantially equal to the surface area of ​​the fourth semiconductor layer 166 away from the second light emitting layer 164 .

[0070] In this embodiment, if Figure 1 As shown, the first end S1 of the second electrode 17 is electrically connected to the second light emitting structure 16 through the second conductive structure 18 , and the second end S2 of the second electrode 17 is electrically connected to the first light emitting structure 11 .

[0071] In this embodiment, if Figure 1 As shown, the first end S1 of the second electrode is overlapped on the side of the fourth conductive layer 182 close to the first light emitting structure 11, so as to realize the electrical connection between the first end S1 of the second electrode and the fourth semiconductor layer 166 of the second light emitting structure 16. The second end S2 of the second electrode is overlapped on the first semiconductor layer 111 of the first light emitting structure 11, so as to realize the electrical connection between the second end S2 of the second electrode and the first semiconductor layer 111 of the first light emitting structure 11.

[0072] In this embodiment, if Figure 1 As shown, the second reflective layer 19 is located between the second electrode 17 and the second light emitting structure 16 , and the projection of the second electrode 17 on the second light emitting structure 16 is located within the projection of the second reflective layer 19 on the second light emitting structure 16 .

[0073] In this embodiment, since the second reflective layer 19 is located between the second electrode 17 and the second light-emitting structure 16, the second reflective layer 19 can reflect the light emitted by the second light-emitting structure 16 toward the second electrode 17 back, thereby preventing the second electrode 17 from absorbing the light emitted by the second light-emitting structure 16, thereby improving the light-emitting efficiency of the light-emitting device.

[0074] In this embodiment, if Figure 1 As shown, the third electrode 21 is a negative electrode. The third electrode 21 is connected to the third semiconductor layer 161 in the second light emitting structure 16. The orthographic projections of the remaining film layers in the second light emitting structure 16 except the third semiconductor layer 161 on the substrate 15 are located within the orthographic projections of the third semiconductor layer 161 on the substrate 15. The third semiconductor layer 161 in the second light emitting structure 16 includes a connecting portion 1611. The orthographic projections of the connecting portion 1611 on the substrate 15 do not overlap with the orthographic projections of the remaining film layers in the second light emitting structure 16 except the third semiconductor layer 161 on the substrate 15. The connecting portion 1611 is located on a side of the third semiconductor layer 161 away from the first light emitting structure 11, and the connecting portion 1611 is connected to the third electrode 21. The third electrode 21 is located on a side of the connecting portion 1611 away from the substrate 15. The orthographic projection of the third electrode 21 on the substrate 15 is located within the orthographic projection of the connecting portion 1611 on the substrate 15.

[0075] In this embodiment, if Figure 1 As shown, the first insulating layer 22 is located between the first light emitting structure 11 and the second light emitting structure 16 , and between the second electrode 17 and the substrate 15 .

[0076] In this embodiment, if Figure 1As shown, one end of the first insulating layer 22 covers the side of the second light-emitting structure 16 facing the first light-emitting structure 11, the side of the third conductive layer 181 facing the first light-emitting structure 11, and the side of the second reflective layer 19 facing the first light-emitting structure 11, and the other end contacts one end of the first semiconductor layer 111 of the first light-emitting structure 11 close to the second light-emitting structure 16.

[0077] In this embodiment, if Figure 1 As shown, the second insulating layer 23 is located on a side of the first light emitting structure 11, the first electrode 12, the first conductive structure 13, the second light emitting structure 16, the second electrode 17, the second conductive structure 18 and the third electrode 21 away from the substrate 15, and covers the substrate 15, the first light emitting structure 11, the first electrode 12, the first conductive structure 13, the second light emitting structure 16, the second electrode 17, the second conductive structure 18 and the third electrode 21. The second insulating layer 23 is used to protect the first light emitting structure 11, the first electrode 12, the first conductive structure 13, the second light emitting structure 16, the second electrode 17, the second conductive structure 18 and the third electrode 21.

[0078] In this embodiment, if Figure 1 As shown, the third reflective layer 24 is located on the side of the second insulating layer 23 away from the substrate 15. The third reflective layer 24 can be a Bragg reflector, and the third reflective layer 24 can be formed by alternating high refractive index materials and low refractive index materials. For example, the third reflective layer 24 can include multiple layers of SiO2 and TiO2 alternately arranged, but is not limited thereto. The thickness of each layer of high refractive index material and the thickness of each layer of low refractive index material are both one-quarter of the central reflection wavelength. The number of layers of high refractive index material is the same as the number of layers of low refractive index material.

[0079] In this embodiment, if Figure 1 As shown, the first conductive portion 25 is electrically connected to the first electrode 12. Part of the first conductive portion 25 is located in a via hole between the second insulating layer 23 and the third reflective layer 24 and is electrically connected to the first electrode 12, and the other part is located on a side of the third reflective layer 24 away from the substrate 15 and is used for electrical connection with the outside.

[0080] In this embodiment, if Figure 1 As shown, the second conductive portion 26 is electrically connected to the third electrode 21. Part of the second conductive portion 26 is located in another via hole between the second insulating layer 23 and the third reflective layer 24 and is electrically connected to the third electrode 21, and the other part is located on a side of the third reflective layer 24 away from the substrate 15 and is used for electrical connection with the outside.

[0081] In this embodiment, the light emitting device may further include a first pad ( Figure 1 ) and the second pad ( Figure 1The first pad and the second pad are located on a side of the third reflective layer 24 away from the substrate 15, the first conductive portion 25 is electrically connected to the first pad, and the second conductive portion 26 is electrically connected to the second pad.

[0082] In this embodiment, if Figure 1 As shown, one end of the first conductive part 25 is electrically connected to the first electrode 12, and the other end is electrically connected to the first pad. One end of the second conductive part 26 is electrically connected to the third electrode 21, and the other end is electrically connected to the second pad.

[0083] The embodiment of the present invention further provides a light emitting device. Figure 1 The light emitting devices shown are substantially the same, except that Figure 2 As shown, the sum of the area of ​​the contact surface between the first conductive layer 131 and the second semiconductor layer 116 and the area of ​​the contact surface between the second conductive layer 132 and the second semiconductor layer 116 is smaller than the area of ​​the surface of the second semiconductor layer 116 away from the first light-emitting layer 114. That is, the portion of the surface of the second semiconductor layer 116 away from the first light-emitting layer 114 is covered by the first conductive structure 13. In this way, under the condition that the current driving the first light-emitting structure 11 remains unchanged, the light-emitting area of ​​the first light-emitting structure 11 is reduced, and the current density can be increased, thereby improving the light-emitting efficiency of the light-emitting device and making the light-emitting efficiency of the light-emitting device more stable. For a schematic diagram of the relationship between current density and light-emitting efficiency, please refer to Figure 3 The unit of current density is milliampere per square centimeter. The unit of luminous efficiency is luminous flux per unit area.

[0084] In this embodiment, if Figure 2 As shown, the sum of the area of ​​the contact surface between the third conductive layer 181 and the fourth semiconductor layer 166 and the area of ​​the contact surface between the fourth conductive layer 182 and the fourth semiconductor layer 166 is smaller than the area of ​​the surface of the fourth semiconductor layer 166 away from the second light emitting layer 164. That is, the portion of the surface of the fourth semiconductor layer 166 away from the second light emitting layer 164 is covered by the second conductive structure 18. In this way, under the condition that the current driving the second light emitting structure 16 remains unchanged, the light emitting area of ​​the second light emitting structure 16 is reduced, the current density can be increased, and the light emitting efficiency of the light emitting device is improved and the light emitting efficiency of the light emitting device is made more stable.

[0085] The embodiment of the present invention further provides a light emitting device. Figure 1 The light emitting devices shown are substantially the same, except that Figure 4As shown, the first conductive layer 131 is located on the side of the second semiconductor layer 116 away from the first light emitting layer 114, and substantially covers the entire second semiconductor layer 116. The first conductive layer 131 substantially covers the entire second semiconductor layer 116 in two cases, one of which is that the first conductive layer 131 covers the entire second semiconductor layer 116, and the other is that the first conductive layer 131 covers almost the entire second semiconductor layer 116, for example, the ratio of the area of ​​the second semiconductor layer 116 covered by the first conductive layer 131 to the area of ​​the surface of the second semiconductor layer 116 away from the substrate 15 is greater than a preset threshold value, and the preset threshold value is, for example, 90%, but is not limited thereto. For example, a small portion of the second semiconductor layer 116 away from the second light emitting structure 16 is not covered by the first conductive layer 131.

[0086] In this embodiment, Figure 4 As shown, the second conductive layer 132 covers the first reflective layer 14 and the first conductive layer 131, and the projection of the second conductive layer 132 on the second semiconductor layer 116 is located within the projection of the first conductive layer 131 on the second semiconductor layer 116. The second conductive layer 132 substantially covers the entire second semiconductor layer 116.

[0087] In this embodiment, the contact area between the second conductive layer 132 and the first conductive layer 131 is larger, and the electrical connection is more stable.

[0088] In this embodiment, Figure 4 As shown, the third conductive layer 181 substantially covers the entirety of the fourth semiconductor layer 166. The third conductive layer 181 substantially covers the entirety of the fourth semiconductor layer 166 in two cases, one of which is that the third conductive layer 181 covers the entirety of the fourth semiconductor layer 166, and the other is that the third conductive layer 181 covers almost the entirety of the fourth semiconductor layer 166, for example, the ratio of the area of ​​the fourth semiconductor layer 166 covered by the third conductive layer 181 to the area of ​​the surface of the fourth semiconductor layer 166 away from the substrate 15 is greater than a preset threshold value, and the preset threshold value is, for example, 90%, but is not limited thereto. For example, a small portion of the fourth semiconductor layer 166 on one side close to the first light emitting structure 11 is not covered by the third conductive layer 181.

[0089] In this embodiment, Figure 4 As shown, the fourth conductive layer 182 covers the second reflective layer 19 and the third conductive layer 181, and the projection of the fourth conductive layer 182 on the fourth semiconductor layer 166 is located within the projection of the third conductive layer 181 on the fourth semiconductor layer 166. The fourth conductive layer 182 substantially covers the entire fourth semiconductor layer 166.

[0090] In this embodiment, the contact area between the fourth conductive layer 182 and the third conductive layer 181 is larger, and the electrical connection is more stable.

[0091] The embodiment of the present invention further provides a light emitting device. Figure 4 The light emitting devices shown are substantially the same, except that Figure 5 As shown, the first conductive layer 131 covers part of the second semiconductor layer 116, the second conductive layer 132 covers part of the second semiconductor layer 116, and the projection of the second conductive layer 132 on the second semiconductor layer 116 is located within the projection of the first conductive layer 131 on the second semiconductor layer 116. For example, the part of the second semiconductor layer 116 close to the second light emitting structure 16 is not covered by the first conductive layer 131 and the second conductive layer 132. That is, the first conductive structure 13 covers part of the second semiconductor layer 116. In this way, under the condition that the current driving the first light emitting structure 11 remains unchanged, the light emitting area of ​​the first light emitting structure 11 is reduced, the current density can be increased, and then the light emitting efficiency of the light emitting device is improved and the light emitting efficiency of the light emitting device is made more stable.

[0092] In this embodiment, Figure 5 As shown, the third conductive layer 181 covers part of the fourth semiconductor layer 166, the fourth conductive layer 182 covers part of the fourth semiconductor layer 166, and the projection of the fourth conductive layer 182 on the fourth semiconductor layer 166 is located within the projection of the third conductive layer 181 on the fourth semiconductor layer 166. For example, the part of the fourth semiconductor layer 166 away from the first light emitting structure 11 is not covered by the third conductive layer 181 and the fourth conductive layer 182. That is, the part of the fourth semiconductor layer 166 away from the surface of the second light emitting layer 164 is covered by the second conductive structure 18. In this way, under the condition that the current driving the second light emitting structure 16 remains unchanged, the light emitting area of ​​the second light emitting structure 16 is reduced, the current density can be increased, and then the light emitting efficiency of the light emitting device is improved and the light emitting efficiency of the light emitting device is made more stable.

[0093] An embodiment of the present invention further provides a display substrate, comprising a driving backplane and the light-emitting device described in any one of the above embodiments.

[0094] In this embodiment, the light emitting device is electrically connected to the driving backplane, and the driving backplane is used to drive the light emitting device to emit light.

[0095] In this embodiment, since the first reflective layer is located between the first electrode and the first light-emitting structure, the first reflective layer can reflect the light emitted by the first light-emitting structure toward the first electrode back, thereby preventing the first electrode from absorbing the light emitted by the first light-emitting structure, thereby improving the light-emitting efficiency of the light-emitting device.

[0096] It should be noted that the display device in this embodiment can be: electronic paper, mobile phone, tablet computer, television, notebook computer, digital photo frame, navigator, or any other product or component with a display function.

[0097] It should be noted that in the accompanying drawings, the sizes of layers and regions may be exaggerated for clarity of illustration. It is also understood that when an element or layer is referred to as being "on" another element or layer, it may be directly on the other element, or there may be an intermediate layer. In addition, it is understood that when an element or layer is referred to as being "under" another element or layer, it may be directly under the other element, or there may be more than one intermediate layer or element. In addition, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it may be the only layer between the two layers or two elements, or there may also be more than one intermediate layer or element. Similar reference numerals throughout the text indicate similar elements.

[0098] In the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0099] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be regarded as exemplary only, and the true scope and spirit of the present invention is indicated by the following claims.

[0100] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A light emitting device, characterized in that: include: A first light emitting structure, a first electrode, a first conductive structure and a first reflective layer; The first electrode is electrically connected to the first light-emitting structure through the first conductive structure, the first reflective layer is located between the first electrode and the first light-emitting structure, the projection of the first electrode on the first light-emitting structure is located within the projection of the first reflective layer on the first light-emitting structure, and the material of the first reflective layer is an insulating material; the first conductive structure includes a first conductive layer and a second conductive layer, the first conductive layer is located on the first light-emitting structure and electrically connected to the first light-emitting structure; the first reflective layer is located between the first conductive layer and the second conductive layer, and the second conductive layer overlaps the first conductive layer.

2. The light emitting device according to claim 1, characterized in that: The first reflective layer is a Bragg reflector; The first conductive structure contacts the first light emitting structure.

3. The light emitting device according to claim 2, characterized in that: The first reflective layer is located on a side of the first conductive layer away from the first light-emitting structure, and a projection of the first reflective layer on the first light-emitting structure is located within a projection of the first conductive layer on the first light-emitting structure; the second conductive layer is located on a side of the first reflective layer away from the first conductive layer, and a projection of the first reflective layer on the first light-emitting structure is located within a projection of the second conductive layer on the first light-emitting structure.

4. The light emitting device according to claim 3, characterized in that: The first light emitting structure includes a first semiconductor layer, a first light emitting layer and a second semiconductor layer. The first light emitting layer is located between the first semiconductor layer and the second semiconductor layer. The first electrode is electrically connected to the second semiconductor layer.

5. The light emitting device according to claim 4, characterized in that: The surface of the second semiconductor layer away from the first light emitting layer includes a first region and a second region, and the first region is adjacent to the second region; The first conductive layer is located on a side of the second semiconductor layer away from the first light-emitting layer, and a contact surface between the first conductive layer and the second semiconductor layer is located in the first region; the second conductive layer covers the first reflective layer, the first conductive layer and the second semiconductor layer, and a contact surface between the second conductive layer and the second semiconductor layer is located in the second region; a projection of the first reflective layer on the second semiconductor layer is located in the first region.

6. The light emitting device according to claim 5, characterized in that: The sum of the area of ​​the contact surface between the first conductive layer and the second semiconductor layer and the area of ​​the contact surface between the second conductive layer and the second semiconductor layer is less than or equal to the area of ​​the surface of the second semiconductor layer away from the first light emitting layer.

7. The light emitting device according to claim 4, characterized in that: The first conductive layer is located on a side of the second semiconductor layer away from the first light-emitting layer, and covers part or all of the second semiconductor layer; The second conductive layer covers the first reflective layer and the first conductive layer, and a projection of the second conductive layer on the second semiconductor layer is located within a projection of the first conductive layer on the second semiconductor layer.

8. The light emitting device according to any one of claims 1 to 7, characterized in that: It also includes a second light emitting structure, a second electrode, a second conductive structure and a second reflective layer; The second light emitting structure and the first light emitting structure are connected in series via the second electrode and the second conductive structure; The first end of the second electrode is electrically connected to the second light emitting structure through the second conductive structure, and the second end of the second electrode is electrically connected to the first light emitting structure; The second reflective layer is located between the second electrode and the second light emitting structure, and a projection of the second electrode on the second light emitting structure is located within a projection of the second reflective layer on the second light emitting structure.

9. The light emitting device according to claim 8, characterized in that: The material of the second reflective layer is an insulating material; the second reflective layer is a Bragg reflector; The second reflective layer is located in the second conductive structure, and the second conductive structure is in contact with the second light emitting structure.

10. The light emitting device according to claim 9, characterized in that: The second light emitting structure comprises a third semiconductor layer, a second light emitting layer and a fourth semiconductor layer, the second light emitting layer is located between the third semiconductor layer and the fourth semiconductor layer, and the second electrode is electrically connected to the fourth semiconductor layer; The second conductive structure includes a third conductive layer and a fourth conductive layer, the third conductive layer is located on a side of the fourth semiconductor layer away from the second light-emitting layer, the second reflective layer is located on a side of the third conductive layer away from the fourth semiconductor layer, a projection of the second reflective layer on the fourth semiconductor layer is located within a projection of the third conductive layer on the fourth semiconductor layer, the fourth conductive layer is located on a side of the second reflective layer away from the third conductive layer, and a projection of the second reflective layer on the fourth semiconductor layer is located within a projection of the fourth conductive layer on the fourth semiconductor layer; the fourth conductive layer overlaps the third conductive layer; and the first end of the second electrode is located on a side of the fourth conductive layer away from the fourth semiconductor layer.

11. The light emitting device according to claim 10, characterized in that: The surface of the fourth semiconductor layer away from the second light emitting layer includes a third region and a fourth region, and the third region is adjacent to the fourth region; The contact surface between the third conductive layer and the fourth semiconductor layer is located in the third region; the fourth conductive layer covers part of the second reflective layer, part of the third conductive layer and part of the fourth semiconductor layer, and the contact surface between the fourth conductive layer and the fourth semiconductor layer is located in the fourth region; the projection of the second reflective layer on the fourth semiconductor layer is located in the third region; The sum of the area of ​​the contact surface between the third conductive layer and the fourth semiconductor layer and the area of ​​the contact surface between the fourth conductive layer and the fourth semiconductor layer is less than or equal to the area of ​​the surface of the fourth semiconductor layer away from the second light emitting layer.

12. The light emitting device according to claim 10, characterized in that: The third conductive layer covers part or all of the fourth semiconductor layer; The fourth conductive layer covers the second reflective layer and the third conductive layer, and a projection of the fourth conductive layer on the fourth semiconductor layer is located within a projection of the third conductive layer on the fourth semiconductor layer.

13. A display substrate, characterized in that: include: A driving backplane and a light emitting device according to any one of claims 1 to 12; The light emitting device is electrically connected to the driving backplane.

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