Iii-Nitride Compound Semiconductor Light Emitting Device

• US 20080149917A1
• Filed: 03/05/2005
• Published: 06/26/2008
• Est. Priority Date: 02/05/2004
• Status: Active Grant

• Current Assignee: Epivalley Co., Ltd.
• Original Assignee: Epivalley Co., Ltd.
• Inventors: Park, Joongseo
• Granted Patent: US 7,547,909 B2
• Time in Patent Office: Days
• US Class Current: 257/17
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 5/3406 including strain compensation
• CPC Class Codes: H01S 5/3407 characterised by special barrier layers
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser
• CPC Class Codes: H01S 5/34346 characterised by the materials of the barrier layers

Abstract

The present invention relates to a III-nitride compound semiconductor light emitting device comprising an active layer with the multi-quantum wells interposed between an n-In_xAl_yGa_zN(x+y+z=1, 0<x<1, 0<y<1, 0<z≦1) layer and a p-In_xAl_yGa_zN(x+y+z=1, 0<x<1, 0<y<1, 0<z<1) layer, wherein the active layer comprises an alternate stacking of a quantum-well layer made of In_xGa_1-xN(0.05<x<1) and a sandwich barrier layer, the sandwich barrier layer comprising a first outer barrier layer of In_aGa_1-aN(0<a<0.05), a middle barrier layer of Al_yGa_1-yN(0<y<1) formed on the first outer barrier layer and a second outer barrier layer of In_bGa_1-bN(0<b<0.05) formed on the middle barrier layer, thereby a high-efficiency/high-output light emitting device with high-current and high-temperature properties can be obtained, and it is possible to easily achieve a high-efficiency green light emission at a wavelength equal to or over 500 nm, and high-efficiency near UV light emission.

Claims

1. A III-nitride compound semiconductor light emitting device comprising an active layer with the multi-quantum wells interposed between an n-In_xAl_yGa_zN(x+y+z=1, 0≦

x<

1, 0≦

y<

1, 0<

z≦

1) layer and a p-In_xAl_yGa_zN(x+y+z=1, 0≦

x<

1, 0≦

y<

1, 0<

z≦

1) layer, wherein the active layer comprises an alternate stacking of a quantum-well layer made of In_xGa_1-xN(0.05<

x<

1) and a sandwich barrier layer, the sandwich barrier layer comprising a first outer barrier layer of In_aGa_1-aN(0<

a≦

0.05), a middle barrier layer of Al_yGa_1-yN(0≦

y<

1) formed on the first outer barrier layer and a second outer barrier layer of In_bGa_1-yN(0<

b≦

0.05) formed on the middle barrier layer, and wherein the middle barrier layer has a bandgap energy greater than those of the first and second outer barrier layers.

2. The III-nitride compound semiconductor light emitting device of claim 1, wherein the quantum-well layers are equal to or below 60 Å

in thickness, and the sandwich barrier layer is equal or below 300 Å

in thickness, and the ratio of the sum of the thickness of the first outer barrier layer and the thickness of the second outer barrier layer, (t1), to the thickness of the middle barrier layer, (t2), i.e., t1/t2, is 1/50 to 1/2.

3. The III-nitride compound semiconductor fight emitting device of claim 1, wherein the lowest layer of the active layer, which is in contact with the n-In_xAl_yGa_zN layer, is the first of the quantum well layers made of In_xGa_1-xN, and the uppermost layer of the active layer, which is in contact with the p-In_xAl_yGa_zN layer, is the last of the quantum well layers made of In_xGa_1-xN.

4. The III-nitride compound semiconductor light emitting device of claim 1, wherein the lowest layer of the active layer, which is in contact with the n-In_xAl_yGa_zN layer, and the uppermost layer of the active layer, which is in contact with the p-In_xAl_yGa N layer, are composed of the middle barrier layer of the sandwich barrier layer.