The effect of underlayers on defect-related droop in InGaN-based light-emitting diodes

作者:Wang, Min-Shuai*; Huang, Xiao-Jing; Cai, Xiao-Mei; Yang, Lan; Zheng, Kai
来源:Journal of Materials Science: Materials in Electronics , 2017, 28(15): 10981-10985.
DOI:10.1007/s10854-017-6879-5

摘要

The efficient white light-emitting diodes (LEDs) is thriving and growing enormously, especially in general lighting. However, the output efficiency droop of LEDs with increasing current injection is still a major problem. We show the correlation between different underlayer structures and defect-related efficiency droop in InGaN-based LEDs, which is very useful to understand the mechanism of the efficiency droop problem. The combined underlayer is made of InGaN/GaN superlattice and dilute bulk InGaN. It is found that the efficiency droop performance in the combined underlayer is much better than the superlattice underlayer and bulk InGaN. And the better power efficiency performance have been achieved by the COM-LED with 4% In concentration, which may be due to the better stress relaxation by using more In concentration in InGaN underlayer.