CN211455712U

CN211455712U - Epitaxial structure for improving LED brightness

Info

Publication number: CN211455712U
Application number: CN201921605356.2U
Authority: CN
Inventors: 宁如光; 张银桥; 潘彬; 王向武
Original assignee: Nanchang Kaixun Photoelectric Co ltd
Current assignee: Nanchang Kaixun photoelectric Co.,Ltd.
Priority date: 2019-09-25
Filing date: 2019-09-25
Publication date: 2020-09-08
Anticipated expiration: 2029-09-25

Abstract

The utility model discloses an improve epitaxial structure of LED luminance, the main factor of quantum efficiency is the carrier figure and the electron hole of light-emitting zone to compound probability in deciding at present, with electron and hole restriction as far as at the luminescent layer, can improve the electron hole to compound probability, can realize improving LED luminous efficiency, the utility model discloses in insert multilayer restriction layer in n-AlGaInP waveguide layer and MQW active layer, design through the component makes restriction layer I, restriction layer II and restriction layer III be in the compressive strain, the potential barrier of material consequently uprises, and the ability of restriction electron and hole obtains improving to improve electron and hole to the compound probability in the quantum well, and then improve luminous efficiency.

Description

Epitaxial structure for improving LED brightness

Technical Field

The utility model relates to a semiconductor diode technical field especially relates to an improve epitaxial structure of LED luminance.

Background

The LED is mainly used in the fields of outdoor landscape lighting, indoor decoration lighting, special lighting, common lighting and the like, has low luminous efficiency in early products, is only suitable for simple household appliances and is applied to instruments, but with the generation of high-brightness light-emitting diodes, the LED light source becomes a main light source and replaces other light source forms of common incandescent lamps and the like. Especially, the energy saving and environmental protection performance of the LED is important, about 60 hundred million liters of crude oil can be saved every year, the emission of greenhouse gases such as carbon dioxide is greatly reduced, and the ecological environment is improved, mainly because the energy utilization efficiency of the LED is higher than that of the prior light source. Therefore, the development of the LED has been the subject of improving the luminous efficiency and further saving the electric energy.

The method for improving the luminous efficiency mainly comprises the steps of improving the external quantum efficiency and the internal quantum efficiency, wherein the internal quantum efficiency refers to the efficiency of carriers injected from the electrodes to generate photons through recombination in the luminous zone, and the external quantum efficiency refers to the efficiency of outputting the photons generated through recombination in the luminous zone to the outside of the device. The main factors for determining the internal quantum efficiency are the number of carriers in a light emitting region and the recombination probability of electron hole pairs, electrons and holes are limited in the light emitting layer as much as possible, the recombination probability of the electron hole pairs can be improved, and the purpose of improving the light emitting efficiency of the LED can be achieved.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the defects of the prior art, and inserting a layer of non-doped Al into the n-AlGaInP waveguide layer and the MQW active layer_0.7In_0.3P confinement layer I and undoped (Al)_xGa_1-x)_0.6In_0.4P confinement layer II between MQW active layer and P- (Al)_xGa_1-x)_0.7In_0.3A layer of non-doped Al is inserted into the waveguide layer_0.5In_0.5And the P limiting layer III enables the limiting layer I, the limiting layer II and the limiting layer III to be in compressive strain through the design of components, so that the potential barrier of the material is increased, the capability of limiting electrons and holes is improved, the recombination probability of the electron and hole pairs in the quantum well is improved, and the luminous efficiency is improved.

The technical scheme of the utility model as follows: a structural design of an epitaxial structure for improving the brightness of an LED comprises a GaAs substrate, wherein: the GaAs substrate is sequentially provided with a buffer layer, an AlGaAs/AlAs (DBR) reflecting layer, an n-AlInP limiting layer, an n-AlGaInP waveguide layer and an undoped Al_0.7In_0.3P confinement layer I, undoped (Al)_xGa_1-x)_0.6In_0.4P confinement layer II, MQW active layer, non-doped Al_0.5In_0.5P-confining layer III, P- (Al)_xGa_1-x)_0.7In_0.3A waveguide layer, a p-AlInP limiting layer and a p-GaP current spreading layer, wherein the MQW active layer middle barrier is made of (Al)_xGa_1-x)_0.6In_0.4P, the material of the trap is (Al)_xGa_1-x)_0.5In_0.5P。

Preferably, the thickness of the buffer layer is 0.5 μm, and the doping concentration of the buffer layer is 5 × 10¹⁷cm^-3The thickness of the AlGaAs/AlAs (DBR) reflecting layer is 1.6 μm, and the doping concentration of the AlGaAs/AlAs (DBR) reflecting layer is 2 × 10¹⁸cm^-3The thickness of the n-AlInP limiting layer is 0.5 mu m, and the doping concentration of the n-AlInP limiting layer is 2 × 10¹⁸cm^-3The thickness of the n-AlGaInP waveguide layer is 0.1 μm, and the doping concentration of the n-AlGaInP waveguide layer is 3 × 10¹⁷cm^-3。

Preferably, the non-doped Al_0.7In_0.3The thickness of the P limiting layer I is 20nm, and the non-doped (Al) layer_xGa_1-x)_0.6In_0.4The thickness of the P-limiting layer II is 20 nm.

Preferably, the MQW active layer comprises 15 layers of wells and 15 layers of barriers, the thickness of the MQW active layer is 300nm, the thickness of each layer of well is 10nm, and the thickness of each layer of barrier is 10 nm.

Preferably, not doped with Al_0.5In_0.5The thickness of the P limiting layer III is 20nm, and P- (Al)_xGa_1-x)_0.7In_0.3Waveguide layer thickness of 0.1 μm, p- (Al)_xGa_1-x)_0.7In_0.3The doping concentration of the waveguide layer is 5 × 10¹⁷cm^-3。

It is preferable thatThe thickness of the p-AlInP limiting layer is 0.8 mu m, and the doping concentration of the p-AlInP limiting layer is 6 × 10¹⁷cm^-3The thickness of the p-GaP current spreading layer is 5 μm, and the doping concentration of the p-GaP current spreading layer is more than 1 × 10¹⁸cm^-3。

The utility model discloses a technological effect and advantage:

1. inserting a layer of non-doped Al into the n-AlGaInP waveguide layer and the MQW active layer_0.7In_0.3P confinement layer I and undoped (Al)_xGa_1-x)_0.6In_0.4And the limiting layer I has an In component lower than that of the limiting layer II, the In component of the limiting layer II is lower than that of the well, on one hand, the In component is low, the potential barrier is high, on the other hand, the In component is low, the lattice parameter is small, and the material is subjected to compressive strain, so that the potential barrier of the material is higher, and the limiting capability on holes is better than that of an AlGaInP material with a normal In component of 0.5.

2. In the MQW active layer and p- (Al)_xGa_1-x)_0.7In_0.3A layer of non-doped Al is inserted into the P waveguide layer_0.5In_0.5And the P limiting layer III enhances the limiting capability on electrons, so that the number of electron-hole pairs in the MQW active layer is increased, and the recombination probability of the electron-hole pairs is improved.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a cross-sectional view of the MQW active layer of the present invention.

Fig. 3 is a schematic view of the structure design of the LED epitaxial wafer of the present invention.

In the figure: a 100-GaAs substrate; 101-a buffer layer; 102-AlGaAs/AlAs (DBR) reflective layer; a 103-n-AlInP confinement layer; 104-n-AlGaInP waveguide layer; 105-non-doped Al_0.7In_0.3A P confinement layer I; 106-undoped (Al)_xGa_1-x)_0.6In_0.4A P confinement layer II; 107-MQW active layer; 108-non-doped Al_0.5In_0.5A P confinement layer III; 109-p- (Al)_xGa_1-x)_0.7In_0.3A waveguide layer; a 110-p-AlInP confinement layer; a 111-p-GaP current spreading layer.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Embodiment 1, referring to fig. 1, an epitaxial structure for improving LED brightness includes a GaAs substrate 100, wherein: a buffer layer 101, an AlGaAs/AlAs (DBR) reflective layer 102, an n-AlInP limiting layer 103, an n-AlGaInP waveguide layer 104, and an undoped Al layer sequentially arranged on the GaAs substrate 100_0.7In_0.3P confinement layer I105, undoped (Al)_xGa_1-x)_0.6In_0.4P confinement layer II 106, MQW active layer 107, non-doped Al_0.5In_0.5P-confining layer III 108, P- (Al)_xGa_1-x)_0.7In_0.3A waveguide layer 109, a p-AlInP limiting layer 110 and a p-GaP current spreading layer 111, wherein the composite MQW active layer 105 is made of (Al)_xGa_1-x)_0.6In_0.4P, the material of the trap is (Al)_xGa_1-x)_0.5In_0.5P。

Embodiment 2, referring to fig. 1, an epitaxial structure for improving LED brightness, wherein the thickness of the buffer layer 101 is 0.5 μm, and the doping concentration of the buffer layer 101 is 5 × 10¹⁷cm^-3The AlGaAs/AlAs (DBR) reflective layer 102 has a thickness of 1.6 μm, and the AlGaAs/AlAs (DBR) reflective layer 102 has a doping concentration of 2 × 10¹⁸cm^-3The thickness of the n-AlInP limiting layer 103 is 0.5 μm, and the doping concentration of the n-AlInP limiting layer 103 is 2 × 10¹⁸cm^-3The n-AlGaInP waveguide layer 104 has a thickness of 0.1 μm and the n-AlGaInP waveguide layer 104 has a doping concentration of 3 × 10¹⁷cm^-3. The rest is the same as example 1.

Embodiment 3, please refer to fig. 1 and fig. 3, an epitaxial structure for improving the brightness of an LED, wherein: the non-doped Al_0.7In_0.3The thickness of the P-limiting layer I105 is 20nm, and the non-doped (Al)_xGa_1-x)_0.6In_0.4The thickness of the P confinement layer II 106 was 20 nm. The rest is the same as example 1.

Embodiment 4, referring to fig. 1 and fig. 2, an epitaxial structure for improving the brightness of an LED, wherein: the composite MQW active layer 107 comprises 15 quantum wells 107-1 and 15 quantum barriers 107-2, the thickness of the MQW active layer 107 is 300nm, and the thickness of each quantum well 107-1 and quantum barrier 107-2 is 10 nm. The rest is the same as example 1.

Embodiment 5, please refer to fig. 1 and fig. 3, an epitaxial structure for improving the brightness of an LED, wherein: the non-doped Al_0.5In_0.5The thickness of the P limiting layer III 108 is 20nm, and the P- (Al) is_xGa_1-x)_0.7In_0.3The waveguide layer 109 has a thickness of 0.1 μm, p- (Al)_xGa_1-x)_0.7In_0.3The waveguide layer 109 has a doping concentration of 5 × 10¹⁷cm^-3. The rest is the same as example 1.

Example 6 referring to fig. 1 and 3, an epitaxial structure for improving LED brightness is disclosed, wherein the p-AlInP confinement layer 110 has a thickness of 0.8 μm, and the p-AlInP confinement layer 110 has a doping concentration of 6 × 10¹⁷cm^-3The thickness of the p-GaP current spreading layer 111 is 5 μm, and the doping concentration of the p-GaP current spreading layer 111 is more than 1 × 10¹⁸cm^-3. The rest is the same as example 1.

The above, only be the utility model discloses a preferred embodiment, it is not right the utility model discloses do any restriction, all according to the utility model discloses the technical entity all still belongs to any simple modification, change and the equivalent structure change of doing above embodiment the utility model discloses technical scheme's within the scope of protection.

Claims

1. An epitaxial structure for improving the brightness of an LED, comprising a GaAs substrate (100), characterized in that: the GaAs substrate (100) is sequentially provided with a buffer layer (101), an AlGaAs/AlAs (DBR) reflecting layer (102), an n-AlInP limiting layer (103), an n-AlGaInP waveguide layer (104) and an Al-undoped Al waveguide layer_0.7In_0.3P confinement layer I (105), undoped (Al)_xGa_1-x)_0.6In_0.4P confinement layer II (106), MQW active layer (107), undopedAl_0.5In_0.5P-confinement layer III (108), P- (Al)_xGa_1-x)_0.7In_0.3A waveguide layer (109), a p-AlInP limiting layer (110) and a p-GaP current spreading layer (111), wherein the MQW active layer (107) is a barrier material (Al)_xGa_1-x)_0.6In_0.4P, the material of the trap is (Al)_xGa_1-x)_0.5In_0.5P。

2. The epitaxial structure of claim 1, wherein the epitaxial structure is characterized in that: the non-doped Al_0.7In_0.3The thickness of the P-limiting layer I (105) is 20nm, and the non-doped (Al)_xGa_1-x)_0.6In_0.4The thickness of the P confinement layer II (106) is 20 nm.

3. The epitaxial structure of claim 1, wherein the epitaxial structure is characterized in that: the MQW active layer (107) comprises 15 layers of wells (107-1) and 15 layers of barriers (107-2), the thickness of the MQW active layer (107) is 300nm, the thickness of each layer of well (107-1) is 10nm, and the thickness of each layer of barrier (107-2) is 10 nm.

4. The epitaxial structure of claim 1, wherein the epitaxial structure is characterized in that: the non-doped Al_0.5In_0.5The thickness of the P limiting layer III (108) is 20nm, and the P- (Al) is_xGa_1-x)_0.7In_0.3The waveguide layer (109) has a thickness of 0.1 μm.