Highly textured single-crystal-like perovskite films for large-area, high-performance photodiodes

Organometallic perovskite single crystals have been considered one of the most promising candidates for photodetection applications, owing to their grain-boundary-free structure and improved optoelectronic properties. However, several challenges still remain for the application of perovskite single crystals in photodetectors, in particular the thickness and area controls and poor compatibility with substrates. Herein, we report a straightforward fabrication process for realizing large-area (up to 100 cm²) and highly textured single-crystal-like MAPbBr₃ films by combining inverse-temperature crystallization with a hot-pressing process. Thanks to the following hot-pressing treatment, the obtained perovskites can be effectively integrated onto the FTO substrates without falling, facilitating electrical connections and device integration. The obtained MAPbBr₃ exhibits a low trap density of 1.4 × 10¹¹ cm⁻³ and a high mobility of 217 cm²·V⁻¹·s⁻¹ (with a high mobility-lifetime product of up to 5.4 × 10⁻⁴ cm²·V^-1). The resulting photodiodes exhibit the self-powered capability and show a maximum responsivity approaching 944 mA·W⁻¹, a champion detectivity exceeding 10¹¹ Jones, and a fast photoresponse of 45 ms, together with excellent stability. This study constitutes a demonstration of highly textured, large-area perovskite photodiodes integrated sturdily onto FTO substrates and paves the way for various practical applications, such as optical imaging technology.