Woven Fibrous Photodetectors for Scalable UV Optical Communication Device

Abstract Fibrous photodetectors (FPDs) have attracted great interest in wearable and consumer electronics, which is a lightweight and flexible tools to achieve efficient light information transmission. However, there is a necessary compromise between high optoelectronic performance and high‐level integration. Herein, a woven optoelectronic keyboard consisting of 40 PD button units is extended and integrated from four individual FPDs, with the integration level expanding by 1000%. Each FPD is based on uniform type‐II TiO 2 /Cs 3 Cu 2 I 5 heterojunction, which exhibits greatly reduced dark current by eight orders of magnitudes, large rectification ratio up to 33306@± 5V, high on–off ratio of 2.8 × 10 4 @−1 V and self‐powered responsivity of 26.9 mA W −1 . The vacuum‐deposited Cs 3 Cu 2 I 5 nanoparticles finely passivate the massive defects and serve as a p‐type hole transport layer to improve hole transfer efficiency, which greatly promotes the radial transport and collection of photogenerated electrons. Moreover, the photocurrent remains highly stable after bending and twisting states. Intriguingly, the woven optoelectronic keyboards successfully realize logic AND/OR, further identifying the UV light signal as a keying text signal (“A–Z” letters, “0–9” numbers, and four punctuations). This work not only provides a scalable strategy to reduce device redundancy but also shows the great potential of fibrous photodetectors for wearable optical communication.