Lead free perovskite solar cells based on a CsSnI3 light absorber with a spectral response from 950 nm is demonstrated. The high photocurrents noted in the system are a consequence of SnF2 addition which reduces defect concentrations and hence the background charge carrier density.
Wolfgang Richard Tress, Simone Meloni, Björn Niesen, Juan-Pablo Correa-Baena, Zaiwei Wang, Chien-Jen Yang, Mozhgan Yavari, Firouzeh Ebadi Garjan
Michael Graetzel, Wolfgang Richard Tress, Ulf Anders Hagfeldt, Konrad Domanski, Essa Awadh R Alharbi, Brian Irving Carlsen, Anand Agarwalla