Flexible Self‐Powered Photodetector Enabled by TeSeO Amorphous‐Crystalline Hybrid

ABSTRACT Flexible photodetectors are critical components in emerging wearable, biomedical, and portable imaging technologies, requiring materials that combine mechanical flexibility with high electronic performance. Conventional crystalline semiconductors require high processing temperatures and are prone to grain boundary fragility, while amorphous ones provide flexibility but are constrained by low charge transport and limited spectral response. Here, we report a p ‐type TeSeO thin film synthesized via thermal evaporation, forming an amorphous‐crystalline hybrid semiconductor that merges the structural compliance of amorphous domains with the superior transport properties of crystalline regions. When integrated with ZnO to construct the flexible heterojunction photodetector, the resulting heterojunction enables efficient charge separation and a broadband spectral response without any external bias. The device exhibits high performance, including a wide detection range from 255 to 1315 nm, ultrafast response with rise and decay times of 52.8 and 51.0 µs, respectively, and a detectivity of 1.81 × 10 11 Jones at 850 nm, while maintaining negligible performance loss after 1000 bending cycles. Demonstrations in biomedical sensing (heart‐rate monitoring) and secure optical communication highlight its broad applicability in wearable optoelectronics. This work establishes amorphous‐crystalline hybrids as a promising platform for realizing broadband, self‐powered, and mechanically robust flexible photodetectors.