Unveiling Surface Recombination Velocity Influence on the Device Characteristics for the Formamidinium Perovskite Solar Cell

Abstract

Herein, we numerically elucidate the effect of varying surface recombination velocity (Srv) at the front and back metal contact on the device performance for our reported lead-free formamidinium tin triiodide (FASnI3) perovskite solar cell. The Srv is generally contemplated as a trivial non-radiative recombination loss factor but determinately impacts the characteristics of the solar cell. Given that, we simultaneously varied the Srv at the back and front metal contacts in the range of 1×101–1×107 cm/s. Such values for Srv can be realized by ideally passivating the perovskite film and with passivated perovskite films or metallic contact resistive nature. It was inferred that at Srv of 1×107 cm/s, the device efficiency was 21.24% and was steeply increased to 21.42% after decreasing the Srv rate to 1×101 cm/s, revealing that recombination losses are enhanced at a higher Srv rate because of increased carrier recombination at the defect surface, thereby reducing the efficiency and overall performance of the solar cell.