GaN-based micro-LEDs and detectors defined by current spreading layer: size-dependent characteristics and their multifunctional applications

An integrated device of GaN-based micro-LED and detector was developed for multifunctional applications in visible light communication (VLC). The size of the current spreading layer was used to define the micro-LED size for high-bandwidth transmitter. The device can also be used as high-sensitivity photodetector (PD). In this scenario, the light receiving area is not restricted by the size of the current spreading layer. The size-dependent characteristics of the PD have been investigated in detail. Such integrated devices can be used as both micro-LED and PD for duplex high-speed VLC. Besides, we demonstrated the functions of solid-state lighting and VLC when the device was integrated with broad-area LED, as well as the potential application in micro-LED display combining with VLC.