High-Sensitivity Self-Powered Photodetector Fibers Using Hierarchical Heterojunction Photoelectrodes Enable Wearable...

Fiber-shaped photodetectors (FPDs) with multidirectional light absorption properties offer exciting opportunities for intelligent optoelectronic textiles. However, achieving FPDs capable of working in ampule environments, especially with high sensitivity, remains a fundamental challenge. Here, quasi-solid-state twisted-fiber photoelectrochemical photodetectors (FPPDs) consisting of photoanode, gel electrolyte, and counter electrode are successfully assembled. In situ decorated n-type one-dimensional (1D) TiO₂ nanowire arrays with 2D Ni-Fe metal-organic framework (NiFeMOF) nanosheets serve as hierarchical heterojunction photoanodes, thereby optimizing carrier transfer dynamics at the photoanode/electrolyte interface. As expected, the resulting self-powered FPPD exhibits 88.6 mA W^-1 high responsiveness and a < 30 ms fast response time. Significantly, our FPPD can operate in both terrestrial and aquatic environments thanks to its intrinsic ionic properties, making it a versatile tool for detecting ultraviolet light on land and facilitating optical communication underwater. These high-sensitivity self-powered FPPDs with hierarchical heterojunction photoelectrodes hold promise for the development of wearable amphibious optoelectronic textiles.