Estimating internal quantum efficiency of light-emitting diodes from current–voltage curves

This work presents an approach to estimate the internal quantum efficiency (IQE) of commercial visible light-emitting diodes (LEDs) with the I-V characteristics. A narrow range of I-V curve, where the ideality factor is minimum, is chosen to be fitted by a parallel model of different current components. Then the IQE in this current range is calculated as the proportion of radiative recombination current and used as a reference to deduce the IQE from the external quantum efficiency. With this method, it founds that the peak IQE of blue and red LEDs exceeds 90% while that of green ones exceeds 60%. (C) 2019 The Japan Society of Applied Physics