The role of polarization fields in Auger-induced efficiency droop in nitride-based light-emitting diodes

Abstract

The rates of non-radiative Auger recombination (AR) and radiative recombination (RR) in polar GaN/AlN quantum wells (QWs) are calculated. It is shown that in these QWs the polarization field not only suppresses the RR but also strongly enhances the rate of AR. As a result, the polarization field triggers the Auger-induced efficiency droop, which, according to the calculations, does not exist in non-polar GaN/AlN QWs. We demonstrate that in polar QWs the droop can be overcome by suppression of AR using a gradual variation of the QW layer composition, which compensates the effect of the electric field acting on holes.