Temperature-dependent efficiency droop in InGaN-based light-emitting diodes induced by current crowding

Temperature-dependent internal quantum efficiency (IQE) of multiple quantum well InGaN/GaN light-emitting diodes (LEDs) has been investigated. IQE versus current relation is analysed using the modified rate equation model that takes into account the current crowding effect at different temperatures. The results of calculations are consistent with the fact that droop in IQE at higher currents originates from Auger recombination increased by current crowding. It is shown that unusual experimentally observed temperature dependence of the efficiency droop can be explained by stronger lateral nonuniformity of carrier injection at low temperatures without any assumptions about carrier delocalization from In-rich regions in quantum wells.