Open-circuit Voltage Loss in CH3NH3SnI3 Perovskite Solar Cells

Organic-inorganic perovskite solar cells based on tin halides exhibit a small open-circuit voltage (VOC) because of a large photon energy loss from band-gap energy, as large as 0.8-1.0 eV. In this study, we discussed the origin of the VOC loss in CH3NH3SnI3-based devices by measuring the temperature dependence of VOC. As a result, we found that the large loss in VOC is mainly due to the surface recombination at the interface rather than the bulk recombination in the perovskites.