Kinetic Monte Carlo simulations of the dynamics of a coupled system of free and localized carriers in AlGaN

A model for the dynamics of a coupled system of free and localized carriers in semiconductors with strong carrier localization is suggested. Kinetic Monte Carlo technique is exploited for simulations. The model is verified by fitting the simulated and experimental temperature dependences of photoluminescence (PL) band intensity, peak position, and band width, and the carrier density dependence of PL efficiency in AlGaN quantum wells. The influence of carrier localization conditions on the dominating carrier migration and recombination processes is revealed. The efficiency droop effect is shown to be caused by peculiarities of carrier localization without significant influence of Auger recombination.