1306.5292 (Fan Yang et al.)

Defect recombination induced by density-activated carrier diffusion in
nonpolar InGaN quantum wells    [PDF]

Fan Yang, Chunfeng Zhang, Chentian Shi, Min Joo Park, Joon Seop Kwak, Sukkoo Jung, Yoon-Ho Choi, Xuewei Wu, Xiaoyong Wang, Min Xiao

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.

View original: http://arxiv.org/abs/1306.5292