Nanogroove-Guided CsPbBr ₃ Nanowire Arrays on Bendable Plastic Enable High-Performance Flexible Photodetectors for Image Sensing and Transmission

Perovskite nanowires offer exceptional optoelectronic properties, yet their large-scale integration into flexible optoelectronics faces challenges, including the inability to achieve epitaxial growth on amorphous flexible substrates and vulnerability of perovskites to degradation during postgrowth assembly. This work presents a nanogroove-guided crystallization strategy that enables in-plane aligned growth of CsPbBr₃ nanowires on bendable poly(ethylene naphthalate) (PEN) at 50 °C. By combining nanogrooved polydimethylsiloxane (PDMS) stamps and wettability-engineered PEN substrates, the method creates aligned nanochannels with vertically asymmetric wettability, guiding unidirectional nanowire growth without requiring lattice-matching or high-temperature processing. This approach facilitates transfer-free flexible device integration via in situ electrode deposition, preserving the nanowire's intrinsic optoelectronic properties. The resulting flexible photodetector combines a responsivity of up to 909.9 A W⁻¹, detectivity of up to 7.35 × 10¹³ Jones, response speed as fast as ∼50 μs, wide linear dynamic range of 89.5 dB, and robust mechanical stability─withstanding over 2000 bending cycles at a severe bending radius of 0.5 cm, underscoring the benefits of transfer-free flexible integration in harnessing the exceptional optoelectronic properties of perovskite nanowires. Last, their proof-of-concept application is showcased in optical image sensing and wireless image transmission. This study provides a scalable, low-temperature, and lattice-match-free pathway for integrating perovskite nanowires into high-performance flexible optoelectronics.