Influence of polarization field on the lasing properties of III-nitride quantum wells

Abstract

A theoretical investigation of the effect of polarization-induced fields on the optoelectronic properties of a 3 nm In 0.2Ga 0.8N/GaN single quantum well has been carried out via a self-consistent solution of Schrödinger–Poisson equations within the effective mass approximation. A pronounced, non-monotonic dependence of the threshold current density J th on the well width has been found due to the enhanced quantum-confined Stark effect. Furthermore, the dependence of threshold current density on the value of the electric field in the well was examined. The threshold current in the 3 nm In 0.2Ga 0.8N/GaN well is higher by a factor of 2–5 compared to an identical well with zero internal field E int. We show that the ability to reduce or eliminate internal fields appears attractive for the improvement of the optoelectronic properties of nitride-based laser diodes and one of achieving this is by using field-compensated quaternary InAlGaN/GaN heterostructures.