Saliba, MichaelOrlandi, SimonettaMatsui, TaisukeAghazada, SadigCavazzini, MarcoCorrea-Baena, Juan-PabloGao, PengScopelliti, RosarioMosconi, EdoardoDahmen, Klaus-HermannDe Angelis, FilippoAbate, AntonioHagfeldt, AndersPozzi, GianlucaGraetzel, MichaelNazeeruddin, Mohammad Khaja2017-03-112017-03-112017-03-11201610.1038/nenergy.2015.17https://infoscience.epfl.ch/handle/20.500.14299/135221WOS:000394096700002Soln.-processable perovskite solar cells have recently achieved certified power conversion efficiencies of over 20%, challenging the long-standing perception that high efficiencies must come at high costs. One major bottleneck for increasing the efficiency even further is the lack of suitable hole-transporting materials, which ext. pos. charges from the active light absorber and transmit them to the electrode. In this work, we present a molecularly engineered hole-transport material with a simple dissym. fluorene-dithiophene (FDT) core substituted by N,N-di-p-methoxyphenylamine donor groups, which can be easily modified, providing the blueprint for a family of potentially low-cost hole-transport materials. We use FDT on state-of-the-art devices and achieve power conversion efficiencies of 20.2% which compare favorably with control devices with 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD). Thus, this new hole transporter has the potential to replace spiro-OMeTAD.A molecularly engineered hole-transporting material for efficient perovskite solar cellstext::journal::journal article::research article