CN202217699U

CN202217699U - Epitaxial structure for LED

Info

Publication number: CN202217699U
Application number: CN2011203501314U
Authority: CN
Inventors: 林志伟; 蔡建九; 陈凯轩; 林志园
Original assignee: Xiamen Changelight Co Ltd
Current assignee: Xiamen Changelight Co Ltd
Priority date: 2011-09-19
Filing date: 2011-09-19
Publication date: 2012-05-09
Anticipated expiration: 2021-09-19

Abstract

The utility model discloses an epitaxial structure for an LED. A Bragg reflecting layer, a first type limiting layer, an active layer, a second type limiting layer, a current spreading layer are sequentially arranged on a GaAs substrate layer from bottom to top, wherein n groups of quantum well and quantum barriers are alternately arranged to form the active layer, the n is less than or equal to 100 and greater than or equal to 2, and barrier height in a same quantum barrier or in different quantum barriers is distributed in a gradual change manner. The epitaxial structure can enhance the limiting effect of the quantum barriers on electrons, and improve the recombination rate of the electrons and cavities in the quantum barrier, so that the brightness of the LED is improved.

Description

A kind of epitaxial structure of light-emitting diode

Technical field

The utility model relates to the light emitting diode epitaxial structure technical field, especially a kind of epitaxial structure of AlGaInP-series light-emitting diode.

Background technology

Light-emitting diode (LED) is because its low-power consumption, size is little and reliability is high gradually at alternative traditional light source, in recent years along with the progress of led technology, utilize the expansion in field, to the brightness and the higher requirement of luminous efficiency proposition of light-emitting diode.

The reddish yellow light-emitting diode of Gao Liang mainly all is to adopt multiple quantum trap (multiple quantum well at present; MQW) structure is as active layer; Usually light-emitting diode is to give off energy through electronics and hole recombination luminescence in SQW, and the luminous efficiency that therefore will improve light-emitting diode mainly is the recombination rate in electronics and hole in the raising SQW; But because the carrier mobility in hole is littler than the carrier mobility of electronics; The tradition epitaxial structure of light-emitting diode; The barrier height that its quantum is built is identical; It is more much better than than electronics to the restriction in hole that quantum is built, so the recombination rate in electronics and hole is difficult to improve the brightness that just limits light-emitting diode in the SQW.

The utility model content

The technical problem that the utility model will solve provides a kind of epitaxial structure of light-emitting diode, strengthens quantum and builds the restriction to electronics, the recombination rate in electronics and hole in the raising SQW, thereby the brightness that improves light-emitting diode.

For achieving the above object; The technical scheme of the utility model is: a kind of epitaxial structure of light-emitting diode; On the GaAs substrate layer, be followed successively by Bragg reflecting layer, the first type limiting layer, active layer, the second type limiting layer, current extending from bottom to top; Described active layer is built by n group SQW and quantum and is alternately formed, and the barrier height during build wherein 100 >=n >=2, and same quantum is that the barrier height between gradual change type distribution or different quantum are built is that gradual change type distributes.

When the height of potential barrier was the gradual change type distribution during preferred same quantum was built, the barrier height distribution mode that a different quantum are built was identical.

The gradual manner of the barrier height high potential barrier of serving as reasons was gradient to low potential barrier during same quantum was built; Or be gradient to low potential barrier, and then the same flat district of individual barrier height is arranged by high potential barrier; Or be gradient to high potential barrier by low potential barrier; Or be gradient to high potential barrier, and then the same flat district of individual barrier height is arranged by low potential barrier; Or be gradient to high potential barrier by low potential barrier and be gradient to low potential barrier again; Or be gradient to high potential barrier by low potential barrier, and the same flat district of individual barrier height is arranged then, be gradient to low potential barrier at last; Or be gradient to low potential barrier by high potential barrier and be gradient to high potential barrier again; Or be gradient to low potential barrier by high potential barrier, and the same flat district of individual barrier height is arranged then, be gradient to high potential barrier at last.

When the barrier height between preferred different quantum is built was the gradual change type distribution, the barrier height that same quantum is built was constant.

The barrier height gradual manner from bottom to top that the different layers quantum the is built high potential barrier of serving as reasons is gradient to low potential barrier; Or be gradient to low potential barrier by high potential barrier, the same flat district of individual barrier height is arranged then; Or be gradient to high potential barrier by low potential barrier; Or be gradient to high potential barrier by low potential barrier, the same flat district of individual barrier height is arranged then; Or be gradient to high potential barrier by low potential barrier and be gradient to low potential barrier again; Or be gradient to low potential barrier by high potential barrier and be gradient to high potential barrier again; Or be gradient to high potential barrier by low potential barrier, and one section flat district that barrier height is the same is arranged then, be gradient to low potential barrier again; Or be gradient to low potential barrier by high potential barrier, and one section flat district that barrier height is the same is arranged then, be gradient to high potential barrier again.

Above-mentioned quantum is built by (Al _xGa _1-x) _yIn _1-yP three or five compounds of group constitute, and wherein 1>=x>=0.5 can change the barrier height that quantum is built through the change of Al component.

The utility model makes barrier height or the barrier height between the different quantum base in the same quantum base in active layer be that gradual change type distributes; Strengthen quantum greatly and build restriction electronics; Reduce the carrier mobility of electronics; Just can improve the recombination rate of electronics and hole in the SQW, thereby improve the brightness of light-emitting diode.

Description of drawings

Fig. 1 is the utility model principle assumption diagram;

Fig. 2 is a kind of potential barrier figure of the utility model;

Fig. 3 is the another kind of potential barrier figure of the utility model.

Embodiment

Below in conjunction with accompanying drawing and concrete execution mode the utility model is done further explain.

Shown in Figure 1; A kind of epitaxial structure of light-emitting diode; On GaAs substrate layer 1, be followed successively by Bragg reflecting layer 2, the first type limiting layer 3, active layer 4, the second type limiting layer 5, current extending 6 from bottom to top; Described active layer 4 alternately is made up of n group SQW 41 and quantum base 42, and wherein the range of choice of n is 100 >=n >=2, and the barrier height that same quantum is built in 42 is that the barrier height that gradual change type distributes or different quantum is built between 42 is that gradual change type distributes.

Described quantum builds 42 by (Al _xGa _1-x) _yIn _1-yP three or five compounds of group constitute, and wherein 1>=x>=0.5 can change the barrier height that quantum is built through the change of Al component.

Shown in Figure 2, active layer 4 is built 42 by SQW 41 and quantum and is alternately formed each other, and the barrier height distribution mode at different individual quantum base 42 all is identical, is building in the middle of 42 with a quantum, and the barrier height at quantum base 42 evenly is gradient to low by height, through (Al _xGa _1-x) _yIn _1-yAl component in P three or five compounds of group drops to 80% equably from 100% and realizes.

Shown in Figure 3; Active layer 4 is built 42 by SQW 41 and quantum and is alternately formed each other, is building in the middle of 42 with a quantum, and the barrier height at quantum base 42 is constant; But barrier height is gradual change between a different quantum build 42; Its barrier height is gradient to low potential barrier by high potential barrier, and one section flat district that barrier height is the same is arranged then, is gradient to high potential barrier again; Through (Al _xGa _1-x) _yIn _1-yAl component in P three or five compounds of group drops to 70% equably from 90%, and after having grown the Al component then and be 70% the individual identical quantum of m (100>=m>=2) and building, last Al component is increased to 90% by 70% and realizes.

Below only be the utility model preferred embodiment, the change that those skilled in the art does to be equal to by claim all falls into the protection range of this case.

Claims

1. epitaxial structure of light-emitting diode; On the GaAs substrate layer, be followed successively by Bragg reflecting layer, the first type limiting layer, active layer, the second type limiting layer, current extending from bottom to top; It is characterized in that: described active layer is built by n group SQW and quantum and is alternately formed; Barrier height during build wherein 100 >=n >=2, and same quantum is that the barrier height between gradual change type distribution or different quantum are built is that gradual change type distributes.

2. a kind of epitaxial structure of light-emitting diode according to claim 1 is characterized in that: when the height of potential barrier was the gradual change type distribution during same quantum was built, the barrier height distribution mode that a different quantum are built was identical.

3. a kind of epitaxial structure of light-emitting diode according to claim 2 is characterized in that: the gradual manner of the barrier height high potential barrier of serving as reasons was gradient to low potential barrier during same quantum was built; Or be gradient to low potential barrier, and then the same flat district of individual barrier height is arranged by high potential barrier; Or be gradient to high potential barrier by low potential barrier; Or be gradient to high potential barrier, and then the same flat district of individual barrier height is arranged by low potential barrier; Or be gradient to high potential barrier by low potential barrier and be gradient to low potential barrier again; Or be gradient to high potential barrier by low potential barrier, and the same flat district of individual barrier height is arranged then, be gradient to low potential barrier at last; Or be gradient to low potential barrier by high potential barrier and be gradient to high potential barrier again; Or be gradient to low potential barrier by high potential barrier, and the same flat district of individual barrier height is arranged then, be gradient to high potential barrier at last.

4. a kind of epitaxial structure of light-emitting diode according to claim 1 is characterized in that: when the barrier height between different quantum are built was the gradual change type distribution, the barrier height that same quantum is built was constant.

5. a kind of epitaxial structure of light-emitting diode according to claim 4 is characterized in that: the barrier height gradual manner from bottom to top that the different layers quantum the is built high potential barrier of serving as reasons is gradient to low potential barrier; Or be gradient to low potential barrier by high potential barrier, the same flat district of individual barrier height is arranged then; Or be gradient to high potential barrier by low potential barrier; Or be gradient to high potential barrier by low potential barrier, the same flat district of individual barrier height is arranged then; Or be gradient to high potential barrier by low potential barrier and be gradient to low potential barrier again; Or be gradient to low potential barrier by high potential barrier and be gradient to high potential barrier again; Or be gradient to high potential barrier by low potential barrier, and one section flat district that barrier height is the same is arranged then, be gradient to low potential barrier again; Or be gradient to low potential barrier by high potential barrier, and one section flat district that barrier height is the same is arranged then, be gradient to high potential barrier again.

6. according to each described a kind of epitaxial structure of light-emitting diode of claim 1 to 5, it is characterized in that: described quantum is built by (Al _xGa _1-x) _yIn _1-yP three or five compounds of group constitute, wherein 1>=x>=0.5.