Thermal effect on the electroluminescence of InGaN/GaN multiquantum-well light-emitting devices

A steady-state thermal model is presented to investigate the temperature and injection-current dependence of the electroluminescence (EL) in InGaN/GaN multiquantum-well light-emitting devices. The important mechanisms for the carrier dynamics, including thermal emission, recapturing, radiative and nonradiative recombination, are taken into account in this model. From the measured EL spectra, it is found that the S-shaped temperature dependence of the peak energy disappears at a high injection-current level. The temperature-dependent emission energies of the EL spectra are calculated with this model. The band-filling effect and the heating effect are considered in our investigation of this phenomenon, and the simulation results are in fair agreement with the experimental data. It is observed that both the band-filling and heating effects influence the temperature dependence of the EL emission spectra of InGaN/GaN multiquantum-wells. Quantitative discussion reveals that the heating effect becomes more apparent when the device is working at high injection-currents. (C) 2011 Elsevier Ltd. All rights reserved.