Multifunctional GaN-based device for solid state lighting, display, and duplex visible light communication

We proposed a GaN-based device with a novel structure, which has the potential to realize the integration of solid-state lighting (SSL), display, and duplex visible light communication (VLC). The area of carrier injection channel was designed by limiting the current spreading layer, forming size varied micro-LEDs. The reduction of the size made the carrier concentration increase, leading to the shortening of the carrier recombination time and the increasing of the bandwidth. The concept of duplex VLC, based on the micro-LED, was demonstrated. The highest bandwidth could reach 517.87 MHz and the transmission rate was 1.16 Gbps by micro-LED based transmitter. When acted as a photodetector, the device proved the self-powered characteristic. The bandwidth and maximum data rate without external power supply were 12.6 MHz and 60 Mbps, respectively. This work has demonstrated the feasibility of the multi-function integrated chip, and we expect such device has broad prospects for indoor illumination, display, and VLC applications.