Millimeter-long perovskite nanowire arrays by nanogroove-confined recrystallization seamlessly integrated into high-performance photodetectors for optical imaging

The controlled growth of perovskite nanowires along predefined orientations offers significant advantages over traditional post-growth assembly strategies, facilitating their integration into compact functional devices. In this study, a nanogroove-confined recrystallization process is designed for the precise and scalable growth of oriented perovskite nanowires with millimeter lengths and high crystallinity. The process involves annealing a perovskite-containing solution sandwiched between a hydrophobic flat silicon wafer and a hydrophilic faceted sapphire wafer featuring parallel nanogrooves at 90 °C under ambient conditions. By customizing the electrode design, the nanowire arrays can be seamlessly integrated into monolithic photodetectors with large detection areas or into photodetector arrays with multiple microscale detector cells on their growth substrate. This <i>in-situ</i> integration strategy eliminates the need for complex post-growth processing steps. The photodetectors exhibit exceptional responsivity (38.4 A·W⁻¹), detectivity (4.35 × 10¹³ Jones), and response times in tens of microseconds across the ultraviolet–visible–near infrared ray (UV–vis–NIR) spectrum. The seamless integration of the nanowire photodetectors opens avenues for practical applications, including high-contrast optical imaging and efficient data transmission through Morse code encoding, leveraging their high on-off current ratios and rapid response. This innovative approach streamlines the growth of highly oriented perovskite nanowires, facilitating their integration into compact optoelectronic devices.