Temperature-dependent efficiency droop analysis of InGaN MQW light-emitting diode with modified ABC model

Abstract

In this work, the origin of the efficiency droop at high injection current in an InGaN multiple-quantum-well light-emitting diode is suggested to be saturation of the radiative efficiency and insufficient carrier injection efficiency. A simple internal quantum efficiency (IQE) estimation method is developed by modifying the conventional ABC model to include carrier leakage mechanisms such as thermionic emission and carrier overflow, to account for the carrier injection efficiency at high current densities. The results show that thermionic emission and carrier overflow play a dominant role in the carrier leakage mechanism at high injection current. The data obtained from this analysis enable inference of the temperature dependence of the radiative/nonradiative coefficients and carrier leakage mechanisms. In addition, the model predicts the temperature dependence and rationale behind the degradation of the IQE at higher injection currents. Furthermore, the modeled output results show good fit with experimental data.