CN212542465U

CN212542465U - Deep ultraviolet LED with asymmetric energy band electron barrier layer

Info

Publication number: CN212542465U
Application number: CN202021907743.4U
Authority: CN
Inventors: 蔡端俊; 黄生荣
Original assignee: Xiamen Yaoguang Semiconductor Technology Co ltd
Current assignee: Xiamen Yaoguang Semiconductor Technology Co ltd
Priority date: 2020-09-03
Filing date: 2020-09-03
Publication date: 2021-02-12
Anticipated expiration: 2030-09-03

Abstract

The utility model provides a deep ultraviolet LED with an asymmetric energy band electron barrier layer, which comprises a substrate, a buffer layer, an n-type contact layer, an active layer, an asymmetric one-way injection electron barrier layer, a p-type electric conduction layer and a metal electrode layer from bottom to top in sequence; the n-type contact layer is connected with a first electrode; the metal electrode layer is connected with a second electrode. According to the deep ultraviolet LED with the asymmetric energy band electron blocking layer, the asymmetric unidirectional injection electron blocking layer is inserted between the p-type conductive layer and the active layer, the asymmetric unidirectional injection electron blocking layer has a high barrier blocking effect on electrons, and low or no barrier is formed on holes, so that unidirectional hole injection can be realized. The deep ultraviolet LED has asymmetric energy band steps, a high band step is arranged at the bottom of a guide band, a low band step is arranged at the top of a valence band, an asymmetric energy band structure is formed, holes are not blocked by the band steps, electrons are blocked by the high band steps, and the electric injection efficiency and the photoelectric conversion efficiency of the deep ultraviolet LED can be effectively improved.

Description

Deep ultraviolet LED with asymmetric energy band electron barrier layer

Technical Field

The utility model relates to a dark ultraviolet LED technical field, in particular to dark ultraviolet LED with asymmetric energy band electron barrier layer.

Background

The deep ultraviolet LED (hereinafter referred to as UVC-LED) is an inorganic product based on a semiconductor chip technology, has narrow and concentrated spectrum, and has the excellent characteristics of energy conservation, environmental protection, instant use, small volume, maintenance avoidance, long service life, high sterilization efficiency and the like. The deep ultraviolet LED has huge market potential and application prospect, and can be widely applied to the fields of disinfection and sterilization, water and food treatment, biochemical detection, information storage, radar detection, secret communication and the like.

In the research, it is found that the light emitting efficiency of the deep ultraviolet LED is generally low, and some reasons are that the electron injection efficiency is low due to leakage current, and the injection efficiency is reduced due to no light leakage of electrons to the p-layer region of the deep ultraviolet LED, and a parasitic light emitting peak with a long wavelength is also caused, so that the design of the electron blocking layer becomes particularly important.

Patent CN107689406A, published 2018.02.13 discloses a deep ultraviolet LED epitaxial structure using a composite electron blocking layer, which includes a substrate layer, a nucleation layer, an AlN layer, an N-type AlGaN layer, and Al_xGa_1-xN/Al_yGa_1-yThe N-type GaN-based multi-quantum well structure comprises an N multi-quantum well active layer, a composite electron blocking layer, a P-type AlGaN layer and a P-type GaN layer. The composite electron blocking layer can effectively reduce the probability of electron leakage to the p layer area, well inhibit the parasitic luminescence peak of long wavelength, improve the electron injection efficiency, and finally can obviously improve the luminescence performance of the deep ultraviolet LED device.

However, the current deep ultraviolet LED with the asymmetric unidirectional injection electron blocking layer has less research and is difficult to meet the market demand.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems that the research on the current deep ultraviolet LED with an asymmetric unidirectional injection electron blocking layer is less and the market demand is difficult to meet, the utility model provides a deep ultraviolet LED with an asymmetric energy band electron blocking layer, which comprises a substrate, a buffer layer, an n-type contact layer, an active layer, an asymmetric unidirectional injection electron blocking layer, a p-type electric conduction layer and a metal electrode layer from bottom to top in sequence;

the n-type contact layer is connected with a first electrode; the metal electrode layer is connected with a second electrode.

Further, the substrate is made of sapphire, silicon carbide, aluminum nitride or gallium nitride.

Further, the buffer layer is an intermediate-temperature AlN buffer layer or a low-temperature AlN buffer layer.

Further, the n-type contact layer is an n-type nitride layer.

Further, the n-type contact layer is an n-type AlGaN layer.

Further, the active layer is a multiple quantum well active layer.

Further, the asymmetric unidirectional injection electron blocking layer is of a non-uniform AlGaN/AlN ultrathin superlattice structure.

Further, the asymmetric unidirectional injection electron blocking layer is of an AlGaN/AlN multiple quantum well structure with gradually changed components.

Further, the asymmetric unidirectional injection electron blocking layer is a hexagonal boron nitride thin layer, and the thickness of the hexagonal boron nitride thin layer can be 0.35nm to several nanometers.

Further, the p-type electric conduction layer is a p-type AlGaN layer.

Furthermore, the metal material of the metal electrode layer can be Pt, Ni, Rh, Au, Ti, Al or Cu.

Furthermore, the first electrode and the second electrode are made of pure metal, alloy or nonmetal conductive material.

The utility model provides a deep ultraviolet LED with asymmetric energy band electron barrier layer between p type electric conductance layer and active layer, inserts asymmetric one-way injection electron barrier layer, and asymmetric one-way injection electron barrier layer has high potential barrier to the electron and blocks the effect, is low potential barrier or does not have the potential barrier to the hole, can realize one-way hole injection. The deep ultraviolet LED with the asymmetric energy band electron blocking layer is provided with asymmetric energy band steps, a high band step is arranged at the bottom of a conduction band, a low band step is arranged at the top of a valence band, an asymmetric energy band structure is formed, holes are not blocked by the band steps, electrons are blocked by the high band steps, and the electric injection efficiency and the photoelectric conversion efficiency of the deep ultraviolet LED can be effectively improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a schematic structural diagram of a deep ultraviolet LED with an asymmetric energy band electron blocking layer according to the present invention.

Reference numerals:

10 substrate 20 buffer layer 30n type contact layer

40 active layer 50 asymmetric unidirectional injection electron blocking layer 60p type electric conducting layer

70 metal electrode layer 80 first electrode 90 second electrode

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The utility model provides a deep ultraviolet LED with asymmetric energy band electron barrier layer, from bottom to top include substrate 10, buffer layer 20, n type contact layer 30, active layer 40, asymmetric one-way injection electron barrier layer 50, p type electric conduction layer 60 and metal electrode layer 70 in proper order;

the n-type contact layer 30 is connected with a first electrode 80; the metal electrode layer 70 is connected to a second electrode 90.

In particular implementation, as shown in fig. 1, the buffer layer 20 on the substrate 10 is used for relieving the stress of the active layer 40 grown on the substrate 10, so as to improve the crystal quality of the active layer 40;

the active layer 40 is a light emitting layer which performs recombination light emission after carrier transition and functions as a light emitting layer, and the active layer is an active layer which determines a light emitting wavelength;

the asymmetric unidirectional injection electron blocking layer 50 has a high barrier blocking effect on electrons, has a low barrier or no barrier on holes, and can realize unidirectional hole injection;

the p-type conductivity layer 60 serves to provide a critical insulating barrier;

the metal electrode layer 70 is formed of an electrode that forms ohmic contact with the ultra-thin p-type AlGaN layer 50, and the metal electrode layer 70 functions as an electric injection and may have a single-layer or stacked-layer structure. Preferably, the metal electrode layer 70 may be a general metal electrode or a deep ultraviolet transparent electrode. The common metal electrode can be made of one or a combination of more than two of metals such as Pt, Ni, Rh, Au, Ti, Al, Cu and the like, and can also be a metal electrode with a nano structure, such as nano particles, nano wires, nano sheets and the like. The material of the deep ultraviolet transparent electrode can be ITO, AZO and deep ultraviolet transparent conductive materials, such as AlN and SiO₂Boron nitride, metal nano-grids or metal nano-wire networks, etc.

The utility model provides a deep ultraviolet LED with asymmetric energy band electron barrier layer has asymmetric energy band rank, has the high band rank at the bottom of leading the area, has the low band rank on price band top, forms asymmetric energy band structure, makes the hole have no band rank to block, and the electron receives the high band rank to block.

In implementing the above embodiment, the substrate 10 is preferably made of sapphire, silicon carbide, aluminum nitride, or gallium nitride. In particular, the substrate 10 may be made of a material selected from the group consisting of sapphire, silicon, and silicon carbide, preferably, a sapphire substrate, which has many advantages: the production technology is mature, and the device quality is good; the stability is good, and the method can be applied to a high-temperature growth process; high mechanical strength, and easy processing and cleaning.

In implementing the above embodiment, the buffer layer 20 is preferably an intermediate-temperature AlN buffer layer or a low-temperature AlN buffer layer. Specifically, a person skilled in the art may select the buffer layer 20 from the existing buffer material with corresponding effect according to different application requirements of different scenarios, and generally, the buffer layer is more prone to select a medium-temperature AlN buffer layer or a low-temperature AlN buffer layer.

In implementing the above embodiment, it is preferable that the n-type contact layer 30 is an n-type nitride layer.

In implementing the above embodiment, the n-type contact layer 30 is preferably an n-type AlGaN layer. Specifically, the n-type contact layer 30 may be made of an existing nitride material, and preferably, an n-type AlGaN layer is used as the n-type contact layer 30.

In implementing the above embodiments, it is preferable that the active layer 40 is a multiple quantum well active layer. Specifically, for those skilled in the art, a multiple quantum well active layer is often used as the active layer 40 of the deep ultraviolet LED.

In the implementation of the above embodiment, preferably, the asymmetric unidirectional injection electron blocking layer 50 is a non-uniform AlGaN/AlN ultra-thin superlattice structure, and the non-uniform AlGaN/AlN ultra-thin superlattice structure is made of an existing material.

Or, the asymmetric unidirectional injection electron blocking layer 50 is an AlGaN/AlN multiple quantum well structure with gradually changed components, and the AlGaN/AlN multiple quantum well structure with gradually changed components is made of the existing material.

Alternatively, the asymmetric unidirectional electron injection barrier layer 50 is a thin layer of hexagonal boron nitride, which may have a thickness of 0.35nm to several nanometers.

In implementing the above embodiment, preferably, the p-type conductivity layer 60 is a p-type AlGaN layer. Specifically, for those skilled in the art, a p-type AlGaN layer may be selected as the p-type conductivity layer 60.

In the above embodiment, the metal material of the metal electrode layer 70 may be Pt, Ni, Rh, Au, Ti, Al or Cu. Specifically, for those skilled in the art, Pt, Ni, Rh, Au, Ti, Al, or Cu may be selected as the metal electrode layer 70.

In the above embodiment, the first electrode 80 and the second electrode 90 are preferably made of pure metal, alloy or non-metal conductive material. Specifically, the skilled person can select a pure metal, an alloy or a non-metallic conductive material to make the first electrode 80 and the second electrode 90 according to actual requirements.

Although terms such as substrate, buffer layer, n-type contact layer, active layer, asymmetric unidirectional injection electron blocking layer, p-type conductivity layer, first electrode and second electrode are used more often herein, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed in a manner that is inconsistent with the spirit of the invention.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. A deep ultraviolet LED with an asymmetric energy band electron blocking layer is characterized in that: the semiconductor device comprises a substrate (10), a buffer layer (20), an n-type contact layer (30), an active layer (40), an asymmetric unidirectional injection electron blocking layer (50), a p-type electric conduction layer (60) and a metal electrode layer (70) from bottom to top in sequence;

the n-type contact layer (30) is connected with a first electrode (80); the metal electrode layer (70) is connected with a second electrode (90).

2. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the substrate (10) is made of sapphire, silicon carbide, aluminum nitride or gallium nitride.

3. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the buffer layer (20) is an intermediate-temperature AlN buffer layer or a low-temperature AlN buffer layer.

4. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the n-type contact layer (30) is an n-type AlGaN layer.

5. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the active layer (40) is a multiple quantum well active layer.

6. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the asymmetric unidirectional injection electron blocking layer (50) is of a non-uniform AlGaN/AlN ultrathin superlattice structure.

7. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the asymmetric unidirectional injection electron blocking layer (50) is of an AlGaN/AlN multi-quantum well structure with gradually changed components.

8. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the asymmetric unidirectional injection electron blocking layer (50) is a hexagonal boron nitride thin layer.

9. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the p-type conductive layer (60) is a p-type AlGaN layer.

10. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the metal material of the metal electrode layer (70) can be Pt, Ni, Rh, Au, Ti, Al or Cu.

11. The deep ultraviolet LED with an asymmetric band electron blocking layer of claim 1, wherein: the first electrode (80) and the second electrode (90) are made of pure metal, alloy or nonmetal conductive materials.