High Charge Carrier Mobilities and Long Diffusion Lengths in Tin Based Metal Halide Perovskite

Tin (Sn)-based perovskites are promising for lower band gap and tandem solar cells due to their red-shifted band gap towards the infrared region. However, Sn based hybrid metal halide perovskite is well known to suffer rapid photoconductivity decay due to the oxidation of Sn
²⁺
to Sn
⁴⁺
under atmospheric oxygen. Here, the charge carrier dynamics of tin based metal halide perovskite is investigated using optical pump-terahertz probe (OPTP) spectroscopy. Also, the performance of the perovskite films at different annealing temperatures is compared and the best performing temperature is identified. The Sn based perovskite films exhibited a remarkable charge carrier mobility and diffusion length.