Open AccessPerformance improvement of GaN-based LEDs with step stage InGaN/GaN strain relief layers in GaN-based blue LEDs
Author(s) -
Chuan-Lei Jia,
Tongjun Yu,
Huimin Lu,
Zhong Can-tao,
Yan Sun,
Yuzhen Tong,
Guoyi Zhang
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.008444
Subject(s) - light emitting diode , materials science , optoelectronics , wide bandgap semiconductor , electroluminescence , nitride , gallium nitride , layer (electronics) , nanotechnology
The performance of nitride-based LEDs was improved by inserting dual stage and step stage InGaN/GaN strain relief layer (SRL) between the active layer and n-GaN template. The influences of step stage InGaN/GaN SRL on the structure, electrical and optical characteristics of GaN-based LEDs were investigated. The analysis of strain effect on recombination rate based k·p method indicated 12.5% reduction of strain in InGaN/GaN MQWs by inserting SRL with step stage InGaN/GaN structures. The surface morphology was improved and a smaller blue shift in the electroluminescence (EL) spectral with increasing injection current was observed for LEDs with step stage SRL compared with conventional LEDs. The output power of LEDs operating at 20 mA was about 15.3 mW, increased by more than 108% by using step stage InGaN/GaN SRL, which shows great potential of such InGaN/GaN SRL in modulating InGaN/GaN MQWs optical properties based on its strain relief function.