Determining External Quantum Efficiency From Energy Conversion Efficiency for Light-Emitting Diodes

We propose a convenient method for estimating external quantum efficiency (EQE) of light-emitting diode directly from the energy conversion efficiency, based on two facts. One lies in that the EQE approximately reaches its maximum when the power source provides the amount of energy that equals the electroluminescence peak energy ( {E}_{\textsf {ELp}} ) to every electron. For the other, an electron carrying higher electrical energy than {E}_{\textsf {ELp}} will release its excessive portion to lattice vibration during radiative recombination, thus emitting a photon with the energy around {\text E}_{\textsf {ELp}} . In comparison with traditional methods, our approach maintains a decent accuracy of mostly 0.4%.