Self-assembled Zn phthalocyanine as a robust p-type selective contact in perovskite solar cells

Abstract

The use of self-assembled monolayers (SAMs) as selective charge extracting layers in perovskite solar cells is a great approach to replace the commonly used charge selective contacts, as they can easily modify the interface to enhance the final solar cell performance. Here, we report a novel synthetic approach of the commonly known zinc phtalocyanine (ZnPc) molecule TT1, widely employed in dye-sensitized solar cells and previously used in perovskite solar cells. TT1 is used as a p-type selective contact, and it demonstrates its ability to form SAM on top of the indium tin oxide (ITO) transparent electrode, obtaining higher efficiencies compared to Pedot:PSS based perovskite solar cells. The differences observed, with an enhanced open-circuit voltage and overall efficiency in TT1 devices are correlated with differences in energetics rather than recombination kinetics.