A method for measuring the internal quantum efficiency of InGaN LED emission

A method of measuring the internal quantum efficiency of emission from InGaN LEDs is suggested. It consists in measuring the emission power and electroluminescence cutoff frequency of the LEDs for two small current values from the range where the LED quantum efficiency rises and then calculating the internal quantum efficiency based on the corresponding functional dependence. To determine the internal quantum efficiency at other values of current, the external quantum efficiency versus current has been measured and the emission efficiency from the structure has been calculated based on measuring data for the values of internal and external small-current quantum efficiencys. The reliability of the new method has been checked by comparing results obtained by it and conventional measuring methods.