Tin perovskite/fullerene planar layer photovoltaics: improving the efficiency and stability of lead-free devices

Abstract

The preparation of CsSnI₃ films at room temperature with defect densities low enough for light harvesting in photovoltaic devices is reported, along with a new strategy for improving device stability and evidence that the energetics at the perovskite/fullerene interface is a key determinant of the open-circuit voltage.