InGaN-Based Light-Emitting Diodes With an AlGaN Staircase Electron Blocking Layer

Author

Chang, Shoou-Jinn ; Yu, Sheng-Fu ; Lin, Ray-Ming ; Li, Shuguang ; Chiang, Tsung-Hsun ; Chang, Sheng-Po ; Chen, Chang-Ho

Author_Institution

Coll. of Sci., China Univ. of Pet. (East China), Qingdao, China

Volume

24

Issue

19

fYear

2012

Firstpage

1737

Lastpage

1740

Abstract

In this letter, we investigate the external quantum efficiency (EQE) and efficiency droop characteristics of InGaN-based light-emitting diodes (LEDs) incorporating Al_xGa_1-xN staircase electron blocking layers (EBLs). The LED featuring a composition-stepped EBL (x: 0.21, 0.14, and 0.07) exhibited the highest EQE under low current levels, but a severe efficiency droop at high current levels. In contrast, the LED with a composition-stepped EBL (x: 0.07, 0.14, and 0.21) exhibited a significant improvement in its onset of droop and a mitigated efficiency droop; we ascribe these features to the increased hole injection rate and the decreased built-in electric field.

Keywords

III-V semiconductors; aluminium compounds; gallium compounds; indium compounds; light emitting diodes; wide band gap semiconductors; EQE; InGaN-AlGaN; LED; built-in electric field; composition-stepped EBL; current levels; efhciency droop characteristics; external quantum efhciency; hole injection rate; light-emitting diodes; staircase electron blocking layer; Aluminum gallium nitride; Art; Current density; Educational institutions; Gallium nitride; Light emitting diodes; Quantum well devices; Droop; InGaN; light-emitting diodes (LEDs); staircase electron blocking layer (EBL);

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2012.2213589

Filename

6269920