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)(2)SnI(4) by incorporating SnI(4) in the precursor solutions. It is observed that Sn(4+) produces p-doping effect on the perovskite, which increases the electrical conductivity by 10(5) times. The dopant SnI(4) is also found to improve the film morphology of (PEA)(2)SnI(4), leading to reduced trap states. This doping technique allows us to improve the room temperature mobility of (PEA)(2)SnI(4) field-effect transistors from 0.25 to 0.68 cm(2) 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)(2)SnI(4) films, which show a high power factor of 3.92 μW m(-1) K(-2) at doping ratio of 5 mol %.