Improving light extraction efficiency in InGaN/GaN light-emitting diodes by backside metal coating

GaN-based multiple-quantum well (MQW) light-emitting diodes (LEDs) of green light with thinning process and backside metal coating have been demonstrated. The devices have electrical characteristics similar to those of conventional broad-area devices. However, due to optimum selection for kind and thickness of metals and more light output reflected upward by backside metal coating, the light extraction efficiency is greatly enhanced. These designed devices provide a simple and low-cost manufacture, thus improving the conventional device.