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)2SnI4 by incorporating SnI4 in the precursor solutions. It is observed that Sn4+ produces p-doping effect on the perovskite, which increases the electrical conductivity by 105 times. The dopant SnI4 is also found to improve the film morphology of (PEA)2SnI4, leading to reduced trap states. This doping technique allows us to improve the room temperature mobility of (PEA)2SnI4 field-effect transistors from 0.25 to 0.68 cm2 V−1 s−1 thanks to reduced trapping effects in the doped devices. Moreover, the doping technique enables the characterization and improvement of the thermoelectric performance of (PEA)2SnI4 films, which show a high power factor of 3.92 μW m−1 K−2 at doping ratio of 5 mol %. [Display omitted] •The p-doping effect of Sn4+ on (PEA)2SnI4 is demonstrated and confirmed.•Proper Sn4+ doping can improve the mobilities of (PEA)2SnI4 FETs.•Thermoelectric performance of (PEA)2SnI4 is characterized and enhanced by Sn4+ doping. Inorganic materials; Materials science; Materials chemistry; Devices