Title :
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
Abstract :
In this letter, we investigate the external quantum efficiency (EQE) and efficiency droop characteristics of InGaN-based light-emitting diodes (LEDs) incorporating AlxGa1-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);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2012.2213589
