High-Responsivity Natural-Electrolyte Undersea Photoelectrochemical Photodetector with Self-Powered Cu@GaN Nanowires Network

摘要

Undersea optical communication (UOC) has been considered as the mostpotential next-generation underwater wireless communication technology forocean exploration. Photodetector is the essential component in UOC system,however, the harsh undersea environment like light attenuation and seawatercorrosivity restricts the applications of conventional photodetectors. Herein,a novel natural-electrolyte self-powered photoelectrochemical (PEC) photodetectorbased on core-shell structured Cu@GaN nanowires (NWs) networkis demonstrated and direct utilization of seawater. High quality GaN shellis encapsulated on the Cu NWs network through Ga-coating and high temperaturenitridation processes. A Schottky junction along radial direction hasformed at the Cu/GaN interface due to the outward diffusion of Cu into theGaN layer. Such a structure provides narrowed band detection on blue light aswell as efficient carrier separation. A self-powered undersea PEC photodetectoris designed with a mini-pipes connected device chamber, which allows directindrawing of seawater and blue channel light communication (458 nm). Thisphotodetector works stably for UOC in both shallow and deep-sea conditionsin Pacific Ocean area. It shows a high responsivity up to 5.04 mA W~（?1） and rapidresponse time of 0.68 ms. This photodetector can be easily integrated to marineequipment without waterproof packaging for the future energy-saving UOC.