Wafer-sized 2D perovskite single crystal thin films for UV photodetectors

Abstract

Two-dimensional (2D) organic–inorganic hybrid perovskites are promising for next-generation optoelectronic materials due to their enhanced stability, controllable quantum well thickness and excellent photoelectric properties. The growth of large lateral size, small thickness and high-quality single crystal films is necessary for the practical application of devices. Herein, we report a gas–liquid interface crystalline route to grow BA₂PbBr₄ (BA = CH₃CH₂CH₂CH₂NH₃⁺) single crystal films and achieve wafer size (38 cm²) and thinness as little as 78 nm (aspect ratio > 10⁵). Moreover, an ultraviolet-photodetector of the single crystal thin film presents a dark current of ∼10⁻¹⁴ A, a detectivity of ∼10¹² Jones and fast response time (τ_rise = 9.7 ms and τ_decay = 8.8 ms). Our work provides a way to grow 2D perovskite single crystal films with large size and small thickness, which is significant for the development of perovskite-type high-performance optoelectronic devices.