Internal quantum efficiency in InGaN/GaN multiple-quantum-well light-emitting diodes under temperature and hydrostatic pressure

This study used a numerical model to investigate the internal quantum efficiency in InGaN/GaN multiple-quantum-well light-emitting diodes (MQWLEDs) under varying temperatures and hydrostatic pressures. Finite difference techniques were employed to acquire energy eigenvalues and their corresponding eigenfunctions of MQWLED, and the hole eigenstates were calculated via a k.p method. Our calculations demonstrated that a temperature change could increase the electron and hole capture coefficients, while a change in pressure could decrease them in the quantum well. It was further found that the Huang-Rhys factor of light holes and the splitting of band holes made the highest contributions to hole capture coefficients. Based on these results, radiative and non-radiative recombination (i.e., Auger and Shockley-Read-Hall) and carrier leakage current decrease with increasing pressure and increase with increasing temperature. Increasing pressure by 10 GPa increases the quantum efficiency, while increasing temperature in the range of 300-600℃ has the opposite effect, decreasing it. Comparing this model with other models and experimental data demonstrates the good validity of this model, particularly in light of the multiphonon model. Generally, increasing temperature has a negative effect and increasing pressure has a positive effect on the internal quantum efficiency of these light-emitting diodes.