High-Performance Dual-Band Self-Powered Photoelectrochemical Photodetector Based on Type-I In₂Te₃/Se Heterostructure for Encrypted Optical Communication

Abstract

Self-powered photoelectrochemical (PEC) photodetectors have emerged as promising candidates for optical communication systems owing to the natural compatibility with aqueous environments, simple fabrication processes, excellent detection sensitivity, and flexibly tunable photoresponse. However, existing PEC-based optical communication devices predominantly operate in a single-channel mode (either visible or ultraviolet spectrum), making them inherently vulnerable to signal interception and information leakage. This work presents the first experimental demonstration of secure dual-wavelength optical communication systems employing self-powered PEC photodetectors based on a type-I In₂Te₃/Se heterostructure. This self-powered photodetector shows strong visible-NIR photoresponse, excellent operational stability, fast response of hundreds of microseconds, and high photoresponsivity. Based on this, we developed a dual-wavelength optical communication architecture, comprising a 550/1030 nm free-space transmission system and a 450/550 nm underwater optical communication system to facilitate high-precision encrypted data transmission. These results demonstrate the feasibility of developing dual-band self-powered PEC photodetectors for multiscenario encrypted optical communication applications.