Excess carrier dynamics of InGaN∕GaN multiple-quantum-well light-emitting diodes with various silicon barrier doping profiles

Abstract

This study investigates the carrier dynamics of InGaN∕GaN light-emitting diodes with various doping profiles in the active region by using time-resolved photoluminescence experiments. Excess carrier lifetime strongly depends on excitation intensity when the quantum wells in the active region comprise doped and undoped barriers. The measured lifetime is shorter when the excitation intensity is lower. Competition between radiative recombination in quantum wells with undoped barriers and carrier tunneling from quantum wells with undoped barriers to wells with doped barriers is responsible for this phenomenon. Reducing the excitation intensity causes more carriers to undergo faster recombination in doped quantum wells.