Doping of Sn-based two-dimensional perovskite semiconductor for high-performance field-effect transistors and thermoelectric devices.

Doping is an important technique for semiconductor materials and devices, yet effective and controllable doping of organic-inorganic halide perovskites is still a challenge. Here, we demonstrate a facile way to dope two-dimensional Sn-based perovskite (PEA)SnI by incorporating SnI in the precursor solutions. It is observed that Sn produces p-doping effect on the perovskite, which increases the electrical conductivity by 10 times. The dopant SnI is also found to improve the film morphology of (PEA)SnI, leading to reduced trap states. This doping technique allows us to improve the room temperature mobility of (PEA)SnI field-effect transistors from 0.25 to 0.68 cm V s thanks to reduced trapping effects in the doped devices. Moreover, the doping technique enables the characterization and improvement of the thermoelectric performance of (PEA)SnI films, which show a high power factor of 3.92 μW m K at doping ratio of 5 mol %.