Direct, simple, rapid, and real‐time monitoring of ultraviolet B level in sunlight using a self‐powered and flexible photodetector

Abstract Sunlight‐originated ultraviolet B (UVB) rays influence daily life in both beneficial and detrimental ways, depending upon light power exposure time. Therefore, precise timely UVB irradiance control is of great importance to humans. This study proposes a self‐powered wearable zinc sulfide (ZnS) nanoparticle (NP)‐based UVB‐C detector for the situ monitoring levels ambient environments. The performance ZnS‐based photodetector can be markedly enhanced by constructing vertical p‐n heterojunction testing feasibility detector, employing thin polyethylenimine (PEI) film inhibiting current leakage charge recombination, introducing poly(9,9‐dioctylfluorene‐alt‐N‐[4‐s‐butylphenyl]‐diphenylamine) (TFB) as hole transport layer increase photocurrent enhance response speed. In particular, we demonstrate that ZnS NP/TFB junction device enables direct narrow specific bands from sunlight owing its unique energy band structure absorption characteristics. optimized has fast rise/fall time 50/62 ms, high detectivity 8.20 × 10 Jones, good stability over long‐term storage against mechanical bending under 254‐nm illumination. Our provides new insights into devices implemented facile, precise, rapid estimation various personal healthcare applications. image