Optimization of n-electrode pattern for p-side down vertical InGaN/GaN blue light emitting diodes

Abstract

In this paper, we propose an optimized pattern of n-electrode of p-side down vertical InGaN/GaN blue light emitting diode for uniform distribution of current density and better light extraction efficiency. It is found that the electrode pattern not only affects electrical but also optical and thermal characteristics of InGaN/GaN vertical LED. Simulation results of the optimized n-electrode pattern shows improved performance of vertical LED in terms of I–V characteristic, series resistance, p–n junction temperature, light extraction efficiency, light output power, and ultimately wall plug efficiency. The effect of current spreading layer on optimized n-electrode pattern is also investigated. Series resistance, light output power, light extraction efficiency, and wall plug efficiency of an optimized strip/square patterned vertical LED are improved by 58/55%, 358/334%, 127/122%, and 451/413%, respectively compared to those of conventional single circular patterned vertical LED.