Alcohol soluble porphyrin for the cathode buffer layers of fullerene/perovskite planar heterojunction solar cells

An ionized porphyrin soluble in alcohol is developed as a cathode buffer layer (CBL) material for fullerene/perovskite planar heterojunction solar cells. Compared with the devices with bathocuproine (BCP) CBLs, those with the porphyrin CBLs show an enhanced power conversion efficiency up to 17.5%, which is contributed by the suppressed leakage current, reduced recombination losses and reduced work function by the porphyrin CBLs.174