Study of efficiency droop and carrier localisation in an InGaN/GaN quantum well structure

This is the authors' abstract. We don't add key points for this paper.

It is well known that the efficiency of InGaN LEDs reduces significantly at high injection currents. To date there have been several explanations for this phenomena, although no consensus has emerged as to the controlling mechanism(s). In this paper we report on the temperature dependence of the photoluminescence emission from an InGaN/GaN quantum well structure as a function of excitation level. We have observed a reduction in the S‐shape temperature dependence of the peak of the emission spectrum at an excitation level that coincides with the onset of the efficiency droop. We suggest that both the efficiency droop and the reduction in the observed S‐shape temperature dependence are caused by saturation of the available localised states within the quantum well. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)