Heating effect on electroluminescence spectra of InGaN/GaN heterostructures

A steady-state rate-equation model is presented to investigate the temperature and injection current dependences of the electroluminescence (EL) for InGaN/GaN multi-quantum-well heterostructures. The important mechanisms of carrier dynamics, including thermal emission, recapturing, radiative and nonradiative recombination, are taken into account in this model. The S-shaped temperature dependence of the peak energy from the EL spectra are demonstrated to be in fair agreement with the carrier motion and thermalization process through hopping over localized states within the indium-rich regions. With increasing injection currents, the S-shaped dependences gradually disappear. The band-filling effect and the heating effect are considered to investigate this phenomenon. It is observed that the EL peak energy is strongly dependent on working temperature and injection current.