Rate equation analysis of efficiency droop in InGaN light-emitting diodes

Efficiency droop in InGaN light-emitting diodes (LEDs) is analyzed based on the rate equation model. By using the peak point of the efficiency versus current-density relation as the parameters of the rate equation analysis, internal quantum efficiency and each recombination current at arbitrary current density can be unambiguously determined without any knowledge of A, B, and C coefficients. The theoretical analysis is compared with measured efficiency of a LED sample and good agreement between the model and experiment is found. The investigation of recombination coefficients shows that Auger recombination alone is not sufficient to explain the efficiency droop of InGaN LEDs.