Vapour-deposited high-performance tin perovskite transistors

Solution-processed tin (Sn2+)-halide perovskites can be used to create p-channel thin-film transistors (TFTs) with performance levels comparable with commercial low-temperature polysilicon technology. However, high-quality perovskite film deposition using industry-compatible production techniques remains challenging. Here we report the fabrication of p-channel Sn2+-halide perovskite TFTs using a thermal evaporation approach with inorganic caesium tin iodide (CsSnI3). We use lead chloride (PbCl2) as a reaction initiator that triggers solid-state reactions of the as-evaporated perovskite compounds. This promotes the conversion of dense and uniform perovskite films, and also modulates the intrinsically high hole density of the CsSnI3 perovskite channels. Our optimized TFTs exhibit average hole field-effect mobilities of around 33.8 cm2 V−1 s−1, on/off current ratios of around 108, and large-area fabrication uniformity. The devices also exhibit improved stability compared with solution-deposited devices. Using a thermal evaporation approach and lead chloride (PbCl2) as a reaction initiator, caesium tin iodide (CsSnI3)-based p-channel thin-film transistors can be fabricated that exhibit average hole field-effect mobilities of around 33.8 cm2 V−1 s−1 and improved stability compared with solution-deposited devices.