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

• Published in: Advanced functional materials 2023-07, Vol.33 (29), p.n/a
• Main Authors: Chen, Han, Lin, Zefeng, Qiu, Hongwei, Tang, Yan, Yang, Shini, Zhao, Jingtian, Zhou, Qicheng, Wang, Jun, Liu, Guozhen, Zhao, Yang, Chen, Dongsheng, Luo, Zhibin, Xu, Feiya, Huang, Shengli, Chen, Xiaohong, Li, Shuping, Cai, Duanjun, Kang, Junyong
• Format: Article
• Language: English
• Subjects: Communication; copper nanowires; Core-shell structure; Diffusion layers; Electrolytes; High temperature; Light attenuation; Materials science; Nanowires; Optical communication; photodetectors; Photometers; Seawater; self‐powered devices; Undersea; Underwater communication; underwater optical communication; Wireless communications
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202302872

Undersea optical communication (UOC) has been considered as the most potential next‐generation underwater wireless communication technology for ocean exploration. Photodetector is the essential component in UOC system, however, the harsh undersea environment like light attenuation and seawater corrosivity restricts the applications of conventional photodetectors. Herein, a novel natural‐electrolyte self‐powered photoelectrochemical (PEC) photodetector based on core‐shell structured Cu@GaN nanowires (NWs) network is demonstrated and direct utilization of seawater. High quality GaN shell is encapsulated on the Cu NWs network through Ga‐coating and high temperature nitridation processes. A Schottky junction along radial direction has formed at the Cu/GaN interface due to the outward diffusion of Cu into the GaN layer. Such a structure provides narrowed band detection on blue light as well as efficient carrier separation. A self‐powered undersea PEC photodetector is designed with a mini‐pipes connected device chamber, which allows direct indrawing of seawater and blue channel light communication (458 nm). This photodetector works stably for UOC in both shallow and deep‐sea conditions in Pacific Ocean area. It shows a high responsivity up to 5.04 mA W−1 and rapid response time of 0.68 ms. This photodetector can be easily integrated to marine equipment without waterproof packaging for the future energy‐saving UOC. A novel type natural‐electrolyte and self‐powered photoelectrochemical photodetector is proposed with Cu@GaN nanowires network for undersea optical communication. A Schottky junction at the Cu/GaN interface enables a narrowed band detection on blue light as well as efficient carrier separation. A high responsivity up to 5.04 mA W−1 is achieved and the device works stably in real undersea circumstance in Pacific Ocean.