We report on the observation of carrier-diffusion-induced defect emission at high excitation density in a-plane InGaN single quantum wells. When increasing excitation density in a relatively high regime, we observed the emergence of defect-related emission together with a significant reduction in bandedge emission efficiency. The experimental results can be well explained with the density-activated carrier diffusion from localized states to defect states. Such a scenario of density-activated defect recombination, as confirmed by the dependences of photoluminescence on the excitation photon energy and temperature, is a plausible origin of efficiency droop in a-plane InGaN quantum-well light-emitting diodes.
@article{arxiv.1306.5292,
title = {Defect recombination induced by density-activated carrier diffusion in nonpolar InGaN quantum wells},
author = {Fan Yang and Chunfeng Zhang and Chentian Shi and Min Joo Park and Joon Seop Kwak and Sukkoo Jung and Yoon-Ho Choi and Xuewei Wu and Xiaoyong Wang and Min Xiao},
journal= {arXiv preprint arXiv:1306.5292},
year = {2013}
}