Title :
Enhanced Optical Power of InGaN/GaN Light-Emitting Diode by AlGaN Interlayer and Electron Blocking Layer
Author :
Lee, Sang-Jun ; Cho, Chu-Young ; Hong, Sang-Hyun ; Han, Sang-Heon ; Yoon, Sukho ; Kim, Sung-Tae ; Park, Seong-Ju
Author_Institution :
Sch. of Mater. Sci. & Eng., Gwangju Inst. of Sci. & Technol., Gwangju, South Korea
Abstract :
We report on the effect of an AlGaN interlayer with a low Al composition, which is inserted between multiple quantum wells (MQWs) and an AlGaN electron blocking layer (EBL) in light-emitting diodes (LEDs). The band diagram shows that this interlayer reduces the hole barrier height between the last GaN barrier in MQWs and the AlGaN EBL to enhance the hole injection. The optical output power at 20 mA of LEDs with interlayer is increased by 20% more than that of LEDs without an interlayer. This improvement is attributed to the enhanced radiative recombination rate, which is due to a more uniform hole distribution and higher hole concentration in MQWs.
Keywords :
III-V semiconductors; aluminium compounds; electron-hole recombination; gallium compounds; indium compounds; light emitting diodes; quantum well devices; wide band gap semiconductors; AlGaN; InGaN-GaN; band diagram; barrier layer; electron blocking layer; enhanced optical power; enhanced radiative recombination; hole barrier height reduction; hole concentration; light emitting diode; multiple quantum wells; uniform hole distribution; Aluminum gallium nitride; Charge carrier processes; Electron optics; Gallium nitride; Light emitting diodes; Power generation; Quantum well devices; AlGaN interlayer; InGaN; electron blocking layer (EBL); light-emitting diodes (LEDs);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2012.2217125
