Graphene Quantum Dots Enhanced InGaN/PdO Self-Powered Ultraviolet-Visible Dual-Band Photodetectors for Encrypted Light Communication

With the increasing emphasis on information security, encrypted light communication is receiving more and more attention as an emerging technology. Dual-band photodetectors (PDs) are one of the appropriate receiving terminals for encrypted light communication. This work investigates the great potential of graphene quantum dots (GQDs) enhanced InGaN/PdO PDs in ultraviolet-visible dual -band photodetection. Combining the high photo response of InGaN/PdO heterojunctions in the visible region with the strong absorption of GQDs in the ultraviolet region, the as-prepared PDs exhibit great self-powered performance including high responsivity of 655.2 mA/W@365 nm and 897.8 mA/W@450 nm, and a fast response time of 5.56/9.29 ms. Furthermore, a simple encrypted light communication system based on dual-beam irradiation modes is achieved and the encryption transmission of letters is demonstrated. This work can provide a feasible method for the design of dual-band PDs and verify their potential in encrypted light communication.