Vertical emitting light emitting device based on graphene and dielectric DBR and preparation method thereof

Abstract

The present disclosure provides a vertical emission light emitting device based on graphene and dielectric DBR and a preparation method thereof, the preparation method comprising: epitaxially forming a non-doped GaN layer on a substrate; preparing a dielectric DBR on the non-doped GaN layer; covering a graphene layer on the dielectric DBR; etching the graphene layer and the dielectric DBR to expose the non-doped GaN layer, forming a patterned bottom dielectric DBR; epitaxially forming a GaN merging layer on the exposed area of the non-doped GaN layer and the bottom dielectric DBR; forming an epitaxial body layer on the GaN merging layer; forming a conductive layer on the epitaxial body layer; preparing a patterned top dielectric DBR on the conductive layer, to obtain the vertical emission light emitting device. The preparation method of the vertical emission light emitting device based on graphene and dielectric DBR provided by the present disclosure is simple, and greatly reduces the production cost of the device.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of semiconductor light-emitting devices and graphene, and particularly relates to a vertical emission light-emitting device based on graphene and dielectric DBR and a preparation method. BACKGROUND

[0002] In the past few years, GaN-based vertical emission light-emitting devices have important application value in the fields of visible light communication, optical sensors, displays and atomic clocks due to their unique light-emitting wavelength band (from ultraviolet to green) and superior performance. Although GaN-based vertical emission light-emitting devices have many advantages, there are still some challenges in manufacturing. Unlike the mature arsenide and phosphide systems, if Al x In y Ga 1-x-y N / GaN growth of fully epitaxial DBR (Distributed Bragg Reflection, Distributed Bragg Reflector), will inevitably exist two problems, relatively low refractive index difference and larger lattice mismatch, researchers by introducing dielectric DBR, to increase the reflectivity of DBR and reduce the logarithm of DBR.

[0003] Since the dielectric DBR is generally an amorphous material, it is not realistic to directly epitaxially grow a vertical emission light-emitting device structure on the surface, and people mostly use laser stripping and bonding processes to realize device preparation.

[0004] Therefore, in the process of realizing the concept of the present disclosure, the inventors found that the preparation process of the vertical emission light-emitting device in the related art is complex, difficult to implement and has a very low yield. SUMMARY

[0005] Therefore, in the process of realizing the concept of the present disclosure, the inventors found that the preparation process of the vertical emission light-emitting device in the related art is complex, difficult to implement and has a very low yield.

[0006] An aspect of the present disclosure provides a preparation method of a vertical emission light-emitting device based on graphene and dielectric DBR, comprising:

[0007] Epitaxially growing an undoped GaN layer on a substrate;

[0008] Preparation of a dielectric DBR on the undoped GaN layer;

[0009] Covering a graphene layer on the dielectric DBR;

[0010] Etching the graphene layer and the dielectric DBR to expose the undoped GaN layer, forming a patterned bottom dielectric DBR;

[0011] forming a GaN merging layer on the exposed region of the non-doped GaN layer and the patterned bottom dielectric DBR by epitaxy;

[0012] forming an epitaxial body layer on the GaN merging layer;

[0013] forming a conductive layer on the epitaxial body layer; and

[0014] preparing a patterned top dielectric DBR on the conductive layer to obtain the vertical emission light emitting device.

[0015] According to an embodiment of the present disclosure, the covering the graphene layer on the dielectric DBR comprises:

[0016] the step of covering the single-layer graphene layer on the dielectric DBR or the step of covering the 2-10 layer graphene layer on the dielectric DBR.

[0017] According to an embodiment of the present disclosure, the step of covering the single-layer graphene layer on the dielectric DBR comprises:

[0018] forming a single-layer graphene layer on a copper foil;

[0019] spinning and curing polymethyl methacrylate on the single-layer graphene layer;

[0020] completely etching the foil;

[0021] cleaning the single-layer graphene layer by transferring it into deionized water for multiple times by using a transfer sheet;

[0022] transferring and covering the single-layer graphene layer on the dielectric DBR by using a transfer sheet;

[0023] removing the polymethyl methacrylate to form the single-layer graphene layer.

[0024] According to an embodiment of the present disclosure, the method of forming a GaN merging layer on the exposed region of the non-doped GaN layer and the patterned bottom dielectric DBR by epitaxy comprises:

[0025] growing a GaN merging layer on the exposed region of the non-doped GaN layer and the patterned bottom dielectric DBR by metal organic chemical vapor deposition (MOCVD); wherein the growth temperature is 900-1100℃.

[0026] According to an embodiment of the present disclosure, the step of forming an epitaxial body layer on the GaN merging layer comprises:

[0027] forming an n-type doped GaN electron injection layer on the GaN merging layer;

[0028] forming a quantum well structure active region on the GaN electron injection layer;

[0029] forming a p-doped AlGaN electron blocking layer on the active region;

[0030] forming a p-doped GaN hole injection layer on the AlGaN electron blocking layer;

[0031] forming a heavily p-doped GaN ohmic contact layer on the GaN hole injection layer.

[0032] According to an embodiment of the present disclosure, the above-mentioned epitaxial formation of the GaN merging layer on the exposed area of the non-doped GaN layer and the patterned bottom dielectric DBR includes:

[0033] first growing GaN material on the exposed area of the non-doped GaN layer, and then using the lateral migration of Ga atoms and N atoms on the graphene layer to make the GaN material laterally epitaxial grow and merge into a film when the thickness of the GaN material reaches the thickness of the patterned bottom dielectric DBR, and finally form the GaN merging layer.

[0034] Another aspect of the present disclosure also provides a graphene and dielectric DBR based vertical emission light emitting device, comprising:

[0035] a substrate;

[0036] a non-doped GaN layer formed on the substrate;

[0037] a patterned bottom dielectric DBR formed on the non-doped GaN layer; wherein the patterned bottom dielectric DBR includes a dielectric DBR and a graphene layer; wherein the graphene layer covers the dielectric DBR;

[0038] a GaN merging layer formed on the exposed area of the non-doped GaN layer and the patterned bottom dielectric DBR;

[0039] an epitaxial body layer formed on the GaN merging layer;

[0040] a conductive layer formed on the epitaxial body layer;

[0041] a patterned top dielectric DBR formed on the conductive layer.

[0042] According to an embodiment of the present disclosure, the above-mentioned epitaxial body layer includes:

[0043] an n-doped GaN electron injection layer formed on the GaN merging layer;

[0044] a quantum well structure active region formed on the n-doped GaN electron injection layer;

[0045] A p-type doped AlGaN electron blocking layer is formed on the active region of the aforementioned quantum well structure;

[0046] A p-type doped GaN hole injection layer is formed on the aforementioned p-type doped AlGaN electron blocking layer;

[0047] A heavily doped p-type GaN ohmic contact layer is formed on the aforementioned p-type doped GaN hole injection layer.

[0048] According to embodiments of this disclosure, the above-described dielectric DBR or the above-described patterned top dielectric DBR comprises multiple stacked dielectric film pairs;

[0049] The aforementioned dielectric film pair includes a first dielectric film and a second dielectric film with different refractive indices;

[0050] The material of the first dielectric film or the second dielectric film includes one of Si3N4, TiO2, SiO2, Ta2O5, HfO2, ZrO, and Al2O3.

[0051] The reflectivity of the aforementioned medium DBR is greater than that of the aforementioned patterned top layer medium DBR.

[0052] According to embodiments of this disclosure, the thickness of the undoped GaN layer ranges from 1 nm to 10,000 nm.

[0053] According to embodiments of this disclosure, the vertical emission light emitter based on graphene and dielectric DBR introduces a technique for directly epitaxially growing GaN merging layers on a patterned high-reflectivity dielectric DBR with a graphene film. By utilizing the high mobility of Ga and N atoms in the graphene layer, which is beneficial for the lateral epitaxial merging of GaN materials, the vertical emission light emitter structure can be directly grown on the surface of the amorphous dielectric DBR. This eliminates complex and expensive processes such as laser lift-off and bonding, simplifies subsequent processes, and greatly reduces production difficulty and cost. Attached Figure Description

[0054] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0055] Figure 1 A vertically emitting light source based on graphene and dielectric DBR according to an embodiment of the present disclosure is schematically illustrated; and

[0056] Figure 2 A flowchart illustrating a method for fabricating a vertically emitting light source based on graphene and dielectric DBR according to another embodiment of the present disclosure is shown.

[0057] In the above figures, the meanings of the reference signs are as follows:

[0058] 00. substrate; 01. undoped GaN layer; 02. dielectric DBR; 03. graphene layer; 04. GaN merging layer; 05. n-type doped GaN electron injection layer; 06. quantum well structure active region; 07. p-type doped AlGaN electron blocking layer; 08. p-type doped GaN hole injection layer; 09. heavily doped p-type GaN ohmic contact layer; 10. conductive layer; 11. patterned top dielectric DBR; 12. epitaxial bulk layer; 13. patterned bottom dielectric DBR. DETAILED DESCRIPTION

[0059] Since the dielectric DBR is generally an amorphous material, it is not realistic to directly epitaxially grow a vertical emission light emitting device structure on the surface, and people mostly use the process of laser stripping and bonding to realize device preparation. This traditional method is complex, difficult to implement, and has a very low yield, so we introduce a GaN merging layer directly epitaxially grown on the patterned dielectric DBR with a graphene layer, which takes advantage of the high mobility of Ga atoms and N atoms on the graphene layer, which is conducive to the lateral epitaxial merging of the GaN material into a film. This further enables the direct growth of a vertical emission light emitting device structure on the surface of an amorphous dielectric DBR, eliminating the need for complex processes such as laser stripping and bonding and expensive technology, simplifying the subsequent process flow, and greatly reducing the production difficulty and cost.

[0060] The present disclosure will be further described in detail below in conjunction with the accompanying drawings and examples. It can be understood that the specific examples described herein are only used to explain the present disclosure, and not to limit the present disclosure, and each feature described in the examples can be combined to form multiple alternative schemes. In addition, it should be noted that, for the sake of description, only the parts related to the present disclosure are shown in the drawings, not all structures.

[0061] The present disclosure provides a preparation method of a vertical emission light emitting device based on graphene and dielectric DBR, comprising:

[0062] Epitaxially growing an undoped GaN layer on a substrate;

[0063] Preparing a dielectric DBR on the undoped GaN layer;

[0064] Covering a graphene layer on the dielectric DBR;

[0065] Etching the graphene layer and the dielectric DBR to expose the undoped GaN layer, forming a patterned bottom dielectric DBR;

[0066] Epitaxially forming a GaN merging layer on the exposed area of the undoped GaN layer and the patterned bottom dielectric DBR;

[0067] forming an epitaxial body layer on the GaN merging layer;

[0068] forming a conductive layer on the epitaxial body layer; and

[0069] preparing a patterned top layer dielectric DBR on the conductive layer to obtain a vertical emission light emitting device.

[0070] According to embodiments of the present disclosure, the method of patterning the bottom layer dielectric DBR includes selective wet etching or inductively coupled plasma etching.

[0071] According to embodiments of the present disclosure, the vertical emission light emitting device based on graphene and dielectric DBR adopts a method based on graphene and patterned dielectric DBR to directly grow a vertical emission light emitting device structure on the surface of the dielectric DBR, thereby eliminating complex processes and expensive technologies such as laser lift-off and bonding, simplifying subsequent process flow, greatly reducing production difficulty and cost, and further greatly reducing device production difficulty and cost.

[0072] According to embodiments of the present disclosure, the step of covering the graphene layer on the dielectric DBR includes:

[0073] The step of covering the single-layer graphene layer on the dielectric DBR or the step of covering the 2-10 layer graphene layer on the dielectric DBR.

[0074] According to embodiments of the present disclosure, the step of covering the single-layer graphene layer on the dielectric DBR includes:

[0075] forming a single-layer graphene layer on a copper foil;

[0076] spin-coating and curing polymethyl methacrylate on the single-layer graphene layer;

[0077] completely etching the foil;

[0078] transferring the single-layer graphene layer to deionized water multiple times using a transfer sheet for cleaning;

[0079] transferring and covering the single-layer graphene layer on the dielectric DBR using a transfer sheet;

[0080] removing the polymethyl methacrylate to form a single-layer graphene layer.

[0081] According to embodiments of the present disclosure, the preparation method of covering the multi-layer graphene layer on the dielectric DBR can include the following steps.

[0082] For example, a single-layer graphene layer is first prepared and covered on the dielectric DBR, and then the preparation method of the single-layer graphene layer is repeated to finally obtain a multi-layer graphene layer covered on the dielectric DBR.

[0083] According to embodiments of the present disclosure, the graphene layer can significantly improve the mobility of Ga atoms and N atoms, and facilitate the formation of a GaN merging layer on the patterned underlying medium DBR and the exposed area of the undoped GaN layer.

[0084] According to embodiments of the present disclosure, the method for epitaxially forming a GaN merging layer on the exposed area of the undoped GaN layer and the patterned underlying medium DBR includes:

[0085] Growth of the GaN merging layer on the exposed area of the undoped GaN layer and the patterned underlying medium DBR by a method of metal organic chemical vapor deposition (MOCVD); wherein the growth temperature includes 900-1100°C.

[0086] According to embodiments of the present disclosure, the GaN merging layer is initially grown by selective induction of GaN material on the exposed area of the undoped GaN layer, and when the thickness of the GaN material reaches the thickness of the patterned underlying medium DBR, the lateral mobility of Ga atoms and N atoms is improved by the graphene layer covering the patterned underlying medium DBR, thereby promoting lateral epitaxy of the GaN material, and finally forming the GaN merging layer.

[0087] According to embodiments of the present disclosure, the method for growing the GaN merging layer on the exposed area of the undoped GaN layer and the patterned underlying medium DBR by a method of metal organic chemical vapor deposition (MOCVD) includes a growth temperature of 900-1100°C, for example, 900°C, 950°C, or 1050°C.

[0088] According to embodiments of the present disclosure, the formation of an epitaxial body layer on the GaN merging layer can include the following steps.

[0089] For example, forming an n-type doped GaN electron injection layer on the GaN merging layer;

[0090] Forming a quantum well structure active region on the GaN electron injection layer;

[0091] Forming a p-type doped AlGaN electron blocking layer on the active region;

[0092] Forming a p-type doped GaN hole injection layer on the AlGaN electron blocking layer;

[0093] Forming a heavily doped p-type GaN ohmic contact layer on the GaN hole injection layer.

[0094] According to embodiments of the present disclosure, a patterned conductive layer is evaporated on the heavily doped p-type GaN ohmic contact layer.

[0095] According to an embodiment of the present disclosure, the preparation method of the medium DBR or the top medium DBR includes one of an electron beam evaporation method, a reactive ion sputtering method, an atomic layer deposition method, a plasma enhanced chemical vapor deposition method, and a metal organic chemical vapor deposition method.

[0096] The present disclosure also provides a graphene and medium DBR based vertical emission light emitting device, which can include:

[0097] a substrate;

[0098] an undoped GaN layer formed on the substrate;

[0099] a patterned bottom medium DBR formed on the undoped GaN layer; wherein the patterned bottom medium DBR includes a medium DBR and a graphene layer; and wherein the graphene layer covers the medium DBR;

[0100] a GaN merging layer formed on the exposed region of the undoped GaN layer and the patterned bottom medium DBR;

[0101] an epitaxial body layer formed on the GaN merging layer;

[0102] a conductive layer formed on the epitaxial body layer;

[0103] a patterned top medium DBR formed on the conductive layer.

[0104] According to an embodiment of the present disclosure, the graphene layer covering the medium DBR can be continuous or discontinuous.

[0105] The continuous graphene layer can achieve the growth of the GaN merging layer more quickly. The discontinuous graphene layer can induce the lateral migration of Ga atoms and N atoms, and finally achieve the growth of the GaN merging layer on the patterned bottom medium DBR.

[0106] According to an embodiment of the present disclosure, the epitaxial body layer includes:

[0107] an n-type doped GaN electron injection layer formed on the GaN merging layer;

[0108] a quantum well structure active region formed on the n-type doped GaN electron injection layer;

[0109] a p-type doped AlGaN electron blocking layer formed on the quantum well structure active region;

[0110] a p-type doped GaN hole injection layer formed on the p-type doped AlGaN electron blocking layer;

[0111] a heavily doped p-type GaN ohmic contact layer formed on the p-type doped GaN hole injection layer.

[0112] According to an embodiment of the present disclosure, the n-doped GaN electron injection layer is used to provide electrons, which are injected into the active region;

[0113] According to an embodiment of the present disclosure, the active region of the quantum well structure is a multi-quantum well structure, which is a periodic alternately grown barrier layer and well layer, and the quantum well includes AlGaN / GaN or InGaN / GaN.

[0114] According to an embodiment of the present disclosure, the p-doped AlGaN electron blocking layer is used to reduce electron leakage and provide a sufficient number of holes, so that more carriers are recombined at the quantum well to emit light, thereby increasing the recombination efficiency of electron-hole pairs.

[0115] According to an embodiment of the present disclosure, the p-doped GaN hole injection layer is used to provide holes, which are injected into the active region.

[0116] According to an embodiment of the present disclosure, the heavily doped p-type GaN ohmic contact layer is used to form a better ohmic contact with the P-face metal electrode, thereby reducing the ohmic contact resistance.

[0117] According to an embodiment of the present disclosure, the conductive layer is a patterned transparent conductive layer, which is located between the top layer dielectric DBR and the heavily doped p-type GaN ohmic contact layer, and is used to achieve lateral current spreading, and the material of the patterned transparent conductive layer includes a metal oxide transparent conductive layer or a graphene transparent conductive layer.

[0118] According to an embodiment of the present disclosure, the dielectric DBR or the patterned top layer dielectric DBR includes a plurality of stacked dielectric film pairs.

[0119] The dielectric film pair includes a first dielectric film and a second dielectric film having different refractive indexes.

[0120] The material of the first dielectric film or the second dielectric film includes one of Si3N4, TiO2, SiO2, Ta2O5, HfO2, ZrO, and Al2O3.

[0121] The reflectivity of the dielectric DBR is greater than that of the patterned top layer dielectric DBR.

[0122] According to an embodiment of the present disclosure, the thickness of the undoped GaN layer can include 1 nm to 10,000 nm.

[0123] According to an embodiment of the present disclosure, the thickness of the undoped GaN layer can include 1 nm to 10,000 nm, which is not only conducive to the final vertical emission light effect of the device, but also conducive to the preparation of the patterned bottom layer dielectric DBR and the GaN merging layer during the preparation process.

[0124] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to specific embodiments and drawings.

[0125] Embodiment 1

[0126] Figure 1 A vertical emission light emitting device based on graphene and dielectric DBR is schematically shown according to an embodiment of the present disclosure.

[0127] As shown in Figure 1 , the vertical emission light emitting device based on graphene and dielectric DBR according to an embodiment of the present disclosure comprises, from bottom to top: a substrate 00, which is made of sapphire;

[0128] a non-doped GaN layer 01 formed on the substrate 00; wherein the thickness of the non-doped GaN layer 01 is 4000 nm;

[0129] a patterned bottom dielectric DBR 13 having a rectangular vertical cross-sectional shape and formed on the non-doped GaN layer 01; wherein the patterned bottom dielectric DBR 13 comprises a dielectric DBR 02 and a graphene layer 03; wherein the graphene layer 03 covers the dielectric DBR 02;

[0130] wherein the dielectric DBR 02 has 15 pairs of dielectric films, the first dielectric film is Si3N4 with a thickness of 61.25 nm, and the second dielectric film is SiO2 with a thickness of 87.22 nm, i.e. the material of the dielectric film pairs of the dielectric DBR 02 is Si3N4 / SiO2; wherein the dielectric DBR 02 is covered by a layer of continuous graphene layer 03;

[0131] a GaN merging layer 04 formed on the exposed area of the non-doped GaN layer 01 and the patterned bottom dielectric DBR 13;

[0132] an epitaxial body layer 12 formed on the GaN merging layer; wherein the epitaxial body layer 12 comprises:

[0133] an n-type doped GaN electron injection layer 05, which is an n-type Si doped GaN electron injection layer, formed on the GaN merging layer 04;

[0134] an active region 06 of quantum well structure, which is an In 0.12 Ga 0.88 N / GaN multiple quantum well structure light emitting layer, formed on the n-type doped GaN electron injection layer 05;

[0135] a p-type doped AlGaN electron blocking layer 07, which is a p-type Mg doped AlGaN electron blocking layer, formed on the active region 06 of quantum well structure;

[0136] The p-doped GaN hole injection layer 08 is a p-type Mg-doped GaN hole injection layer formed on the p-doped AlGaN electron blocking layer 07;

[0137] The heavily p-doped GaN ohmic contact layer 09 is a p-type heavily Mg-doped GaN ohmic contact layer formed on the p-doped GaN hole injection layer 08;

[0138] The conductive layer 10 is a patterned transparent conductive layer of metal oxide with a thickness of 30 nm formed on the heavily p-doped GaN ohmic contact layer 09;

[0139] The patterned top layer dielectric DBR 11 is a patterned top layer dielectric DBR with a rectangular vertical cross-sectional shape; the patterned top layer dielectric DBR 11 has 10 pairs of dielectric films, the first dielectric film is Si3N4 with a thickness of 61.25 nm, and the second dielectric film is SiO2 with a thickness of 87.22 nm, i.e., the material of the pairs of dielectric films of the patterned top layer dielectric DBR 11 is Si3N4 / SiO2, and the patterned top layer dielectric DBR 11 is formed on the conductive layer 10.

[0140] Embodiment 2

[0141] Figure 2 A flowchart of a preparation method of a graphene and dielectric DBR-based vertical emission light emitting device according to another embodiment of the present disclosure is schematically shown.

[0142] As shown in Figure 2 The flowchart of the preparation method of the graphene and dielectric DBR-based vertical emission light emitting device includes:

[0143] Step S201: epitaxially growing an undoped GaN layer directly on a substrate.

[0144] Step S202: preparing a dielectric DBR on the undoped GaN layer by a reactive ion sputtering method.

[0145] Step S203: preparing a graphene layer.

[0146] Specifically, a single-layer graphene layer grown by chemical vapor deposition on a Cu foil is spin-coated with polymethyl methacrylate and cured at 120°C for 15 min, and then immersed in a 22% FeCl3 solution for 4 hours to completely etch the Cu foil.

[0147] Step S204: covering the graphene layer on the dielectric DBR.

[0148] Specifically, the single-layer graphene layer is transferred to deionized water multiple times for cleaning by using a transfer sheet, and then the single-layer graphene layer is transferred to a clean dielectric DBR by using a transfer sheet, and after air-drying in a nitrogen cabinet, polymethyl methacrylate on the single-layer graphene layer is removed with acetone and ethanol.

[0149] Step S205: etching the graphene layer and the medium DBR by the method of inductively coupled plasma to expose the undoped GaN layer, and forming a patterned bottom medium DBR.

[0150] Step S206: epitaxially forming a GaN merging layer on the exposed area of the undoped GaN layer and the bottom medium DBR.

[0151] Specifically, the GaN merging layer is grown by the method of metal organic chemical vapor deposition at 1000℃, and in the initial growth stage, the exposed undoped GaN layer is used for selective induction growth of GaN material, and when the thickness of the GaN material reaches the thickness of the patterned bottom medium DBR, the Ga atoms and N atoms are used for lateral epitaxial growth of the GaN material by the high mobility of the graphene layer, and finally the merging film is formed.

[0152] Step S207: forming an epitaxial main layer on the GaN merging layer.

[0153] Specifically, the epitaxial main layer is formed on the GaN merging layer by the method of metal organic chemical vapor deposition, and the n-type Si-doped GaN electron injection layer, the In 0.12 Ga 0.88 N / GaN multi-quantum well light-emitting layer, the Mg-doped AlGaN electron blocking layer, the Mg-doped GaN hole injection layer, and the heavily doped Mg GaN ohmic contact layer are sequentially epitaxially grown from bottom to top.

[0154] According to the embodiment of the present disclosure, the patterned metal oxide transparent conductive layer is evaporated on the heavily doped Mg p-type GaN ohmic contact layer, the evaporation temperature is 220℃, the top medium DBR is prepared by the method of reactive ion sputtering, then the top medium DBR is etched by the method of inductively coupled plasma, and finally the patterned top medium DBR is obtained.

[0155] Step S208: performing the required post-process of the device to obtain a vertical emission light-emitting device based on graphene and medium DBR.

[0156] The above only describes the preferred embodiments of the present disclosure and should not be used to limit the present disclosure, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A method for fabricating a vertical light emitting diode based on graphene and dielectric DBR, characterized in that, The method comprises the following steps: forming an epitaxial undoped GaN layer on a substrate; forming a dielectric DBR on the undoped GaN layer; forming a graphene layer on the dielectric DBR; etching the graphene layer and the dielectric DBR to expose the undoped GaN layer, and forming a patterned bottom dielectric DBR; forming an epitaxial GaN merging layer on the exposed area of the undoped GaN layer and the patterned bottom dielectric DBR; forming an epitaxial main body layer on the GaN merging layer; forming a conductive layer on the epitaxial main body layer; and forming a patterned top dielectric DBR on the conductive layer to obtain the vertical emission light emitting device.

2. The production method according to claim 1, characterized by, The step of forming the graphene layer on the dielectric DBR comprises: the step of forming a single-layer graphene layer on the dielectric DBR or the step of forming a 2-10-layer graphene layer on the dielectric DBR.

3. The preparation method according to claim 2, characterized in that, The step of forming a single-layer graphene layer on the dielectric DBR comprises: forming a single-layer graphene layer on a copper foil; spinning and curing polymethyl methacrylate on the single-layer graphene layer; completely etching the copper foil; transferring the single-layer graphene layer to deionized water multiple times for cleaning by using a transfer sheet; transferring and covering the single-layer graphene layer on the dielectric DBR by using a transfer sheet; removing the polymethyl methacrylate to form the single-layer graphene layer.

4. The preparation method according to claim 1, characterized in that, The method of forming the epitaxial GaN merging layer on the exposed area of the undoped GaN layer and the patterned bottom dielectric DBR comprises: growing the GaN merging layer on the exposed area of the undoped GaN layer and the patterned bottom dielectric DBR by using a metal organic chemical vapor deposition method; wherein the growth temperature comprises 900-1100℃.

5. The preparation method according to claim 1, characterized in that, The step of forming the epitaxial main body layer on the GaN merging layer comprises: forming an n-type doped GaN electron injection layer on the GaN merging layer; forming a quantum well structure active region on the GaN electron injection layer; forming a p-type doped AlGaN electron blocking layer on the active region; forming a p-type doped GaN hole injection layer on the AlGaN electron blocking layer; forming a heavily doped p-type GaN ohmic contact layer on the GaN hole injection layer.

6. The method of claim 1, wherein, The method of forming the epitaxial GaN merging layer on the exposed area of the undoped GaN layer and the patterned bottom dielectric DBR comprises: first growing GaN material on the exposed area of the undoped GaN layer, and then using the lateral migration of Ga atoms and N atoms on the graphene layer to make the GaN material laterally epitaxially grow and merge into a film, and finally form the GaN merging layer when the growth thickness of the GaN material reaches the thickness of the patterned bottom dielectric DBR.

7. A vertical light emitting device based on graphene and DBR, prepared by the method according to any one of claims 1 to 6, wherein the graphene is graphene oxide. The vertical emission light emitting device comprises: a substrate; an undoped GaN layer formed on the substrate; a patterned bottom dielectric DBR formed on the undoped GaN layer; wherein the patterned bottom dielectric DBR comprises a dielectric DBR and a graphene layer; wherein the graphene layer is covered on the dielectric DBR; a GaN merging layer formed on the exposed area of the undoped GaN layer and the patterned bottom dielectric DBR. an epitaxial body layer formed on the GaN merge layer; a conductive layer formed on the epitaxial body layer; a patterned top layer dielectric DBR formed on the conductive layer.

8. The vertical emitting light emitting device of claim 7, wherein, The epitaxial body layer comprises: an n-doped GaN electron injection layer formed on the GaN merge layer; an active region of quantum well structure formed on the n-doped GaN electron injection layer; a p-doped AlGaN electron blocking layer formed on the active region of quantum well structure; a p-doped GaN hole injection layer formed on the p-doped AlGaN electron blocking layer; a heavily p-doped GaN ohmic contact layer formed on the p-doped GaN hole injection layer.

9. The vertical emitting light emitting device of claim 7, wherein, The dielectric DBR or the patterned top layer dielectric DBR comprises a plurality of stacked dielectric film pairs; wherein the dielectric film pair comprises a first dielectric film and a second dielectric film with different refractive indexes; wherein the material of the first dielectric film or the second dielectric film comprises one of Si3N4, TiO2, SiO2, Ta2O5, HfO2, ZrO, Al2O3; wherein the reflectivity of the dielectric DBR is greater than that of the patterned top layer dielectric DBR.

10. The vertical emitting light emitting device of claim 7, wherein, The thickness of the non-doped GaN layer comprises 1 nm to 10,000 nm.

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