The investigation on the interference phenomenon in electroluminescence spectrum of vertical structured InGaAlN multiple quantum well light-emitting diodes

Abstract

The electroluminescence (EL) spectrum of vertical structured InGaN multiple-quantum-well light-emitting diodes were obtained at different space angles. It was found that the multiple EL peak pattern was caused by the interference phenomenon and the distance between the peaks could indicate the thickness uniformity of the p-type layer. The intensity difference between the wave crest and the wave trough of the peak pattern indicates the reflectance ratio of p-type ohmic contact layer. The integral EL intensity in the normal direction of the chip was not so strong， while in the directions of 80° and 75° the intensities were the largest and the interference phenomenon was the sharpest. The intensity of the EL and the interference phenomenon of the side face of the chip was the weakest.