Monte Carlo-drift-diffusion simulation of electron current transport in Ⅲ-N LEDs

摘要

Performance of Ⅲ-N based solid-state lighting is to a large extent limited by current transport effects that are also expected to contribute to the efficiency droop in real devices. To enable studying the contributions of electron transport in drooping more accurately, we develop and study a coupled Monte Carlo-drift-diffusion (MCDD) method to model the details of electron current transport in Ⅲ-N optoelectronic devices. In the MCDD method, electron and hole distributions are first simulated by solving the standard drift-diffusion (DD) equations. The hole density and recombination rate density obtained from solving the DD equations are used as inputs in the Monte Carlo (MC) simulation of the electron system. The MC simulation involves solving the Boltzmann transport equation for the electron gas to accurately describe electron transport. As a hybrid of the DD and MC methods, the MCDD represents a first-order correction for electron transport in Ⅲ-N LEDs as compared to DD, predicting a significant hot electron population in the simulated multi-quantum well (MQW) LED device at strong injection.