Direct Determination of the Internal Quantum Efficiency of Light‐Emitting Diodes

Abstract

The maximum internal quantum efficiency (IQE) of light‐emitting diodes (LEDs) can be obtained using the so‐called ABC model. Since the ABC model is based on the experimentally not directly accessible carrier density, the light over current data is usually fitted as a function of the light output to yield the maximum IQE. This article shows a method to directly obtain the IQE from experimental data without fitting, which also reflects changes of the A, B, or C parameters over the current range.

Recent advances in micro-pixel light emitting diode technology

“…This was first introduced by Dai et al 31 In principle, the IQE for different light outputs can also be obtained using special plots. 32 In any case, it is important to know which of the three ABC factors is responsible for the change in the IQE. Because P ¼ B ffiffiffiffi ffi AC p , only the relationship between A, B, and C can be calculated using P. However, absolute values cannot be obtained from EQE measurements without another independent measurement of the carrier lifetime or the use of modulated currents.…”