Suspended p-n junction InGaN/GaN multiple quantum wells device with bottom silver reflector

In this study, we propose, fabricate, and characterize suspended p-n junction InGaN/GaN multiple quantum wells (MQWs) device with a bottom silver reflector for diverse applications. The suspended device was achieved through a double-side process on the GaN-on-silicon platform and tested by using a micro-reflectance/transmittance setup. When the suspended device operates under the light-emitting diode mode, a fraction of the emitted light reflected by the bottom silver reflector can enter into the air through the top escape cone, leading to improved light extraction efficiency. When the suspended device operates under the photodiode mode, part of the transmitted light can be reflected back by the bottom silver reflector to enhance the photovoltaic effect. The experimental results demonstrate that such suspended device can be used as both transmitter and receiver for visible light communication. And the detecting features even when the suspended structure is under turn-on state, demonstrating a potential realization of light emission and photodetection simultaneously.