Radiative and nonradiative recombination in an ultraviolet GaN/AlGaN multiple-quantum-well laser diode

We have experimentally investigated the radiative and nonradiative recombination in a GaN/AlGaN multiple-quantum-well laser diode. The each carrier lifetime has been evaluated based on a rate equation analysis of light output-current characteristics of the laser diode. The estimated nonradiative carrier lifetime is 830 ps, and the Auger recombination is negligibly small at room temperature. At a threshold current density of 8 kA cm−2, the carrier density and the internal quantum efficiency are estimated to be 2.6×1019 cm−3 and 34%, respectively. These results are responsible for experimental and theoretical analysis of optical and electrical properties in AlGaN-based laser diodes.