Light emitting diode

• US 10,453,992 B2
• Filed: 12/31/2017
• Issued: 10/22/2019
• Est. Priority Date: 04/29/2016
• Status: Active Grant

• Current Assignee: Quanzhou Sanan Semiconductor Technology Co., Ltd. (Sanan Optoelectronics Company Limited)
• Original Assignee: Xiamen San'An Optoelectronics Co.Ltd. (Sanan Optoelectronics Company Limited)
• Inventors: Zheng, Yuan-yu, Zheng, Jiansen, Wu, Mingyue, Chou, Chilun, Qiu, Cai-hua, Luo, Xiao, Lin, Feng, Li, Shuiqing, Wu, Chaoyu, Cai, Kunhuang
• Primary Examiner(s): Rahim, Nilufa
• Application Number:
  US15/859,555
• Publication Number:
  US 20180145210A1
• Time in Patent Office: 660 Days
• Field of Search: 257 94
• CPC Class Codes: H01L 33/0066 with a substrate not being a III-V compound
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/305 characterised by the doping materials

Abstract

An AlGaInP light-emitting diode includes from bottom up a substrate, a distributed Bragg reflector (DBR) reflecting layer, an N-type semiconductor layer, a quantum well light-emitting layer, a P-type semiconductor layer, a transient layer and a P-type current spreading layer. The DBR reflecting layer is multispectral-doping. The P-type semiconductor layer includes a first P-type semiconductor layer adjacent to the quantum well light-emitting layer and a second P-type semiconductor layer adjacent to the transient layer. A doping concentration of the second P-type semiconductor layer is lower than that of the first P-type semiconductor layer. By improving doping concentration of the multispectral DBR reflecting layer, current spreading can be improved, thus improving aging performance. A concentration difference is formed with the transient layer to balance doping of the transient layer; this avoids increasing non-radiation composition from high doping of the transient layer during long-time aging.

Claims

1. An AlGaInP light-emitting diode, comprising from bottom up:

a substrate;

a distributed Bragg reflector (DBR) reflecting layer;

an N-type semiconductor layer;

a quantum well light-emitting layer;

a P-type semiconductor layer;

a transient layer; and

a P-type current spreading layer;

wherein;

the DBR reflecting layer is multispectral-doping, comprising;

a first DBR reflecting layer;

a second DBR reflecting layer; and

a third DBR reflecting layer;

a doping concentration of the first DBR reflecting layer is higher than a doping concentration of the second DBR reflecting layer, and the doping concentration of the second DBR reflecting layer is higher than a doping concentration of the third DBR reflecting layer;

the P-type semiconductor layer comprises;

a first P-type semiconductor layer adjacent to the quantum well light-emitting layer; and

a second P-type semiconductor layer adjacent to the transient layer;

wherein a doping concentration of the second P-type semiconductor layer is lower than a doping concentration of the first P-type semiconductor layer;

wherein a material of the P-type semiconductor layer comprises Al_xIn_(1-x)P, wherein 0<

x<

1.

2. The AlGaInP light-emitting diode of claim 1, configured to be smaller than 50 mil², and with a drive current higher than or equal to 100 mA to improve aging performance.

3. The AlGaInP light-emitting diode of claim 1, wherein the substrate is selected from at least one of GaAs, GaP or Ge suitable for epitaxial growth.

4. The AlGaInP light-emitting diode of claim 1, wherein the doping concentration of the third DBR reflecting layer is 2×

10¹⁸˜

1×

10²⁰ cm<sup>−

3</sup>.

5. The AlGaInP light-emitting diode of claim 1, wherein reflection wave bands of the first DBR reflecting layer, the second DBR reflecting layer and the third DBR reflecting layer are 700-750 nm, 650-700 nm, and 600-650 nm, respectively.

6. The AlGaInP light-emitting diode of claim 1, wherein there are 2-7 pairs of the first DBR reflecting layer, 6-12 pairs of the second DBR reflecting layer, and 13-20 pairs of the third DBR reflecting layer, respectively.

7. The AlGaInP light-emitting diode of claim 1, wherein the doping concentration of the second P-type semiconductor layer is 40%-80% the doping concentration of the first P-type semiconductor layer.

8. The AlGaInP light-emitting diode of claim 1, wherein the doping concentration of the first P-type semiconductor layer is 0.7×

10¹⁸-1.5×

10¹⁸ cm<sup>−

3</sup>, and the doping concentration of the second P-type semiconductor layer is 0.28×

10¹⁸-1.2×

10¹⁸ cm<sup>−

3</sup>.

9. The AlGaInP light-emitting diode of claim 1, wherein a thickness of the second P-type semiconductor layer is 10%-30% of a thickness of the first P-type semiconductor layer.

10. The AlGaInP light-emitting diode of claim 1, wherein a thickness of the first P-type semiconductor layer is 0.3-1.0 μ

m, and a thickness of the second P-type semiconductor layer is 0.03-0.3 μ

m.

11. The AlGaInP light-emitting diode of claim 1, wherein a doping concentration of the transient layer is 1.5×

10¹⁸-4.0×

10¹⁸ cm<sup>−

3</sup>.

12. The AlGaInP light-emitting diode of claim 1, wherein the transient layer adopts Al_xGa_yIn_1-x-y P material for gradient growth of each component, wherein, 0<

x<

1, 0<

y<

1, x+y<

1.

13. The AlGaInP light-emitting diode of claim 1, wherein the DBR reflecting layer adopts multi-spectral DBR, comprising a material of Al_xGa_1-xAs/Al_yGa_1-yAs, where, 0<

x≤

1, 0<

y<

1.

14. The AlGaInP light-emitting diode of claim 1, wherein a doping impurity of the multispectral DBR reflecting layer is any of Si, Sn, S, Se or Te.

15. The AlGaInP light-emitting diode of claim 1, wherein the doping concentration of the first DBR reflecting layer is 7×

10¹⁸-1×

10²⁰ cm<sup>−

3</sup>;

the doping concentration of the second DBR reflecting layer is 5×

10¹⁸-1×

10²⁰ cm<sup>−

3</sup>, which is lower than that of the first DBR reflecting layer; and

the doping concentration of the third DBR reflecting layer is 2×

10¹⁸-1×

10²⁰ cm<sup>−

3</sup>, which is lower than that of the second DBR reflecting layer.

16. The AlGaInP light-emitting diode of claim 1, wherein the N-type semiconductor layer comprises Al_xIn_(1-x)P, where, 0<

x<

1.

17. The AlGaInP light-emitting diode of claim 1, wherein a doping impurity of the N-type semiconductor layer is any of Si, Sn, S, Se or Te.

18. The AlGaInP light-emitting diode of claim 1, wherein an N-type doping concentration of the N-type semiconductor layer is 0.5×

10¹⁸-3.0×

10¹⁸ cm<sup>−

3</sup>.

19. The AlGaInP light-emitting diode of claim 1, wherein a material of the quantum well light-emitting layer is Al_xGa_yIn_1-x-yP, where 0<

x<

1, 0<

y<

1.

20. The AlGaInP light-emitting diode of claim 1, wherein:

a doping impurity of the P-type semiconductor layer comprises at least one of Be, Mg, Zn, Cd, or C.