LAUSR

Abstract We present first-principle computational modelling of the perovskite CsSnxPb(1−x)I3 (x = 0, 0.5 and 1), aimed at increasing the efficiency of perovskite photovoltaics. Using density functional theory calculations with a hybrid functional, we predict that both CsPbI3 and CsSnI3 are stable structures with direct bandgaps, suitable for photovoltaic application. On the other hand, the stable structure of CsSn0.5Pb0.5I3 exhibits an indirect bandgap, which could work as a direct bandgap due to the short electron-hole distance. The results of this study demonstrates that through bandgap engineering, we can obtain larger photon absorption ranges and higher efficiencies for perovskite based photovoltaics.