Correlation between the efficiency droop and the blueshift of the electroluminescence in InGaN/GaN multiple-quantum-well blue light-emitting diodes

Abstract

A correlation between the efficiency droop and the blueshift of the peak wavelength in electroluminescence is experimentally investigated by utilizing InGaN/GaN multiple-quantum-well blue light-emitting diodes with different efficiency droop characteristics. We experimentally observe a clear correlation between these physical quantities and explain it by the increased inhomogeneity of indium incorporated into the InGaN quantum wells (QWs). With more indium in the QWs, the effective active volume becomes smaller due to indium clustering, inducing early saturation of the radiative recombination rate and subsequent droop.