CN-224218764-U - Green light LED chip based on N-type GaN layer embedded DBR structure

CN224218764UCN 224218764 UCN224218764 UCN 224218764UCN-224218764-U

Abstract

The utility model belongs to the technical field of LED chips, and discloses a green LED chip based on an N-type GaN layer embedded DBR structure, which comprises a substrate, and a first buffer layer, a first undoped GaN layer, a green MQW layer, a second undoped GaN layer, an N-type GaN layer, a DBR layer, a second buffer layer, a third undoped GaN layer, a blue MQW layer, an electron blocking layer and a P-type GaN layer which are sequentially deposited on the substrate, wherein an N electrode is arranged on the N-type GaN layer, a P electrode is arranged on the P-type GaN layer, and the DBR layer is formed by periodically alternately laminating two dielectric materials with different refractive indexes. According to the utility model, the DBR layer is embedded between the N-type GaN layer and the blue light quantum well, downward photons are directly reflected, the light extraction efficiency is improved, the photon reflection path is shortened, the absorption loss is reduced, and meanwhile, a low-stress growth template is provided for the blue light quantum well, so that the dislocation density is reduced, and the growth quality of the blue light quantum well is improved.

Inventors

SONG WEIZI
ZHANG CHENGWANG
XIE TAO
YU BIN

Assignees

聚灿光电科技（宿迁）有限公司

Dates

Publication Date: 20260508
Application Date: 20250613

Claims (6)

1. The green light LED chip based on the N-type GaN layer embedded DBR structure is characterized by comprising a substrate, and a first buffer layer, a first undoped GaN layer, a green light MQW layer, a second undoped GaN layer, an N-type GaN layer, a DBR layer, a second buffer layer, a third undoped GaN layer, a blue light MQW layer, an electron blocking layer and a P-type GaN layer which are sequentially deposited on the substrate, wherein an N electrode is arranged on the N-type GaN layer, a P electrode is arranged on the P-type GaN layer, and the DBR layer is formed by periodically and alternately laminating two dielectric materials with different refractive indexes.
2. The green LED chip of claim 1, wherein the first undoped GaN layer, the third undoped GaN layer, and the second undoped GaN layer are sequentially reduced in thickness.
3. The green LED chip of claim 1, wherein the number of periods of alternating layers of the DBR layer is 5-30, the optical thickness of the single layer is λ/(4N), where λ is 380-480nm, and N is the refractive index of the dielectric material.
4. The green LED chip of claim 1, wherein the two dielectric materials are Al 2 O 3 and SiO 2 or Si 3 N 4 and SiO 2 , respectively.
5. The green LED chip of claim 1, wherein the DBR layer has a periodic pattern structure formed on the N-type GaN layer.
6. The green LED chip based on the N-type GaN layer embedded DBR structure of claim 5, wherein the pattern structure is a pyramid structure, a cone structure or a truncated cone structure, and the bottom surface of the pattern structure is polygonal or circular.

Description

Green light LED chip based on N-type GaN layer embedded DBR structure Technical Field The utility model belongs to the technical field of LED chips, and particularly relates to a green LED chip based on an N-type GaN layer embedded DBR structure. Background The traditional green light LED directly grows a blue light quantum well after a filling layer is grown on a sapphire substrate in a 3D mode, dislocation density is high due to lattice mismatch, and Internal Quantum Efficiency (IQE) is limited. The existing DBR is located at the interface of the substrate or the back of the chip, the growth interface of the blue light quantum well cannot be optimized, and absorption loss is caused by long light reflection paths. Therefore, there is a need to optimize the DBR position and the structural design of the green LED chip to reduce the dislocation of the blue quantum well growth and improve the light extraction efficiency of the blue quantum well. Disclosure of utility model Aiming at the defects in the background technology, the utility model provides the green light LED chip based on the N-type GaN layer embedded DBR structure, and the blue light quantum well growth dislocation is reduced by optimizing the position and the structure of the DBR, so that the light emitting efficiency of the blue light quantum well is improved. In order to achieve the above purpose, the technical solution of the present utility model is as follows: The green light LED chip based on the N-type GaN layer embedded DBR structure comprises a substrate, and a first buffer layer, a first undoped GaN layer, a green light MQW layer, a second undoped GaN layer, an N-type GaN layer, a DBR layer, a second buffer layer, a third undoped GaN layer, a blue light MQW layer, an electron blocking layer and a P-type GaN layer which are sequentially deposited on the substrate, wherein an N electrode is arranged on the N-type GaN layer, a P electrode is arranged on the P-type GaN layer, and the DBR layer is formed by periodically and alternately laminating two dielectric materials with different refractive indexes. Preferably, the thicknesses of the first undoped GaN layer, the third undoped GaN layer and the second undoped GaN layer are sequentially reduced. Preferably, the DBR layers have an alternating number of lamination cycles of 5 to 30, a single layer optical thickness of λ/(4 n), where λ is 380 to 480nm, and n is the refractive index of the dielectric material. Preferably, the two dielectric materials are Al 2O3 and SiO 2, or Si 3N4 and SiO 2, respectively. Preferably, the DBR layer forms a periodic pattern structure on the N-type GaN layer. Preferably, the graph structure is a pyramid structure, a cone structure or a truncated cone structure, and the bottom surface of the graph structure is polygonal or circular. Compared with the prior art, the utility model has the following beneficial effects: (1) According to the utility model, the DBR layer is embedded between the N-type GaN layer and the blue light quantum well, downward photons are directly reflected, the light extraction efficiency is improved, the photon reflection path is shortened, the absorption loss is reduced, the patterned structure can also change the light propagation direction more effectively, and meanwhile, a low-stress growth template is provided for the blue light quantum well, so that the dislocation density is reduced, and the growth quality of the blue light quantum well is improved; (2) The DBR layer is selected from Al 2O3/SiO2 or Si 3N4/SiO2, the refractive index difference delta n is more than or equal to 0.2, the thermal expansion coefficient is matched with that of GaN, the problem of stress in the epitaxial layer is solved, and high-temperature cracking is avoided. Drawings Other features, objects and advantages of the present utility model will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the following drawings. FIG. 1 is a schematic diagram of a chip structure according to the present utility model; In the figure, 1, a substrate, 2, a first buffer layer, 3, a first undoped GaN layer, 4, a green light MQW layer, 5, a second undoped GaN layer, 6, an N-type GaN layer, 7, a DBR layer, 8, a second buffer layer, 9, a third undoped GaN layer, 10, a blue light MQW layer, 11, an electron blocking layer, 12, a P-type GaN layer, 13, an N electrode, 14 and a P electrode. Detailed Description The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. In the description of the present utility model, it should be understood that the terms "middle," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indic