A Gate-Assisted Dual-Functional GaN p-n Diode for High-Speed Visible Light Communication

Multifunctional integration is emerging as a critical focus in optical communication research, especially for visible light communication (VLC) systems. A key challenge is developing diodes capable of efficient signal modulation and sensitive detection of superimposed optoelectrical signals, essential for advanced VLC applications. In this work, we integrated a metal-oxide gate terminal (Gt) onto a GaN-based blue diode, significantly improving both emission and detection functionalities. In emitter mode, this integrated approach achieves a 162% improvement in modulation bandwidth, increasing from 98 MHz with a conventional bias-tee to 257 MHz using the Gt configuration. Further, incorporating a reflective electrode with the Gt improves the device’s performance, increasing the light output power by 37% and external quantum efficiency by 34%, resulting in a data rate increase of 14.2%, from 0.89 to 1.03 Gbps. In detector mode, the diode effectively detects high-speed superimposed optoelectrical signals, facilitating secure and efficient communication. This multifunctional diode provides enhanced modulation and detection capabilities, offering a promising platform for next-generation VLC and optical communication systems.