Effect of indium tin oxide (ITO) current spreading layer on the current uniformity of vertical structure GaN-based light-emitting diodes

摘要

Compared with conventional GaN based LEDs structure, vertical electrodes structure can improve the current uniformity to some extend. However, due to the presence of N-GaN series resistance, current crowing phenomenon still exist at the electrode edge of vertical structure GaN-based LEDs. The most common solutions to overcome these problems consist in using transparent current spreading contact layer, generally made of indium tin oxide(ITO). In this paper, the effect of indium tin oxide (ITO) layer on the current uniformity and the current distribution are analyzed by theoretical calculation. At last, vertical structure GaN-based LEDs was fabricated and the electrical character was measured. Experiment result exhibits good agreement with the theoretical calculation.