Organic-inorganic hybrid perovskite solar cells have undergone an unprecedented development as the next-generation photovoltaic devices in recent years.The power conversion efficiency and stability are the key factors attracting great attentions from both academic and industrial communities.Here we insert a nonoxide CdS layer between TiO2 and perovskite to passivate the TiO2 interface in planar-type perovskite solar cells.After introducing the CdS layer,we observe significantly enhanced air stability and suppressed recombination between the trapped electrons and perovskite related with inverse transport.At the optimum CdS thickness,a champion power conversion efficiency of 14.26%is achieved compared with 10.31%for the reference CdS-free devices.This impressive efficiency also surpasses that of previously reported perovskite solar cells based on CdS.The largely improved performance is ascribed to the increased Fermi level of electron transport layer,more efficient charge transport and lower recombination rates.