A D-pi-A Organic Dye as a Passivator to Effectively Regulate the Performance of Perovskite Solar Cells

The lattice defects in perovskite solar cells comprising polycrystalline films affect the cell's humidity stability and photovoltaic performance. Herein, a donor-pi-acceptor organic dye molecule (ZT001) containing a carboxyl group on the acceptor moiety and long alkyl chains on the donor moiety is synthesized and used as an effective passivator in perovskite solar cells. It is revealed in the results that the carboxyl group of ZT001 successfully passivates the film defects by forming coordination with uncoordinated Pb2+, and the humidity stability of the device is improved and maintained above 80% of the original photoelectric conversion efficiency (PCE). Therefore, ZT001-passivated perovskite devices exhibit a superior PCE of 20.6% compared with the PCE of unpassivated devices (19.5%).