Bismuth perovskite as a viable alternative to Pb perovskite solar cells: device simulations to delineate critical efficiency dynamics

Abstract

We have simulated the operation and functionality of a working Bi-based perovskite solar cell device using GPVDM and compared it against a Pb-based device. The results are extremely promising in that they showcase comparable cell efficiencies, with the Bi-based device showing a highest 20.0% efficiency (Jsc of 256 A.m-2, Voc of 1.04 V, FF of 0.75) at 450 nm active layer thickness compared to 23.4% of its Pb counterpart (Jsc of 349.3 A.m-2, Voc of 0.81 V, FF of 0.83) at 850 nm active layer thickness. The Bi-based device can thus be manufactured at approximately half its Pb-counterpart active layer thickness, to give its optimal efficiency value. A deeper study of each of the Jsc, Voc and FF trends provide keen insight into charge transfer kinetics within the device, paving the way to optimal experimental setups for fabricating the most efficient non-toxic perovskite devices.