Evaluation of internal quantum efficiency in blue and green light-emitting diodes using rate equation model

A convenient and reliable method for the determination of internal quantum efficiency (IQE) in GaN-based light-emitting diodes (LEDs) is presented. By using the peak point of the efficiency curve as the parameter of the carrier rate equation model, IQE of LEDs is shown to be unambiguously determined without any information on the recombination coefficients or LED structures. The theoretical analysis model was used to determine IQE of LED samples. When the theoretical IQE model is applied to the measured external quantum efficiency (EQE) of a blue and a green LED, good agreements between the measured data and the theoretical fit curves are found.