Impact of peripheral groups on novel asymmetric phthalocyanine-based hole-transporting materials for perovskite solar cells

摘要： Three novel asymmetrical substituted phthalocyaninecobalt with nitro and (4-butyl formate) phenoxy, (4-propenyl-2-methoxy) phenoxy or (4-methyl formate) phenoxy as different bulky peripheral groups (CoPcNO2-OBFPh, CoPcNO2-OPMPh, CoPcNO2-OMFPh) are successfully developed and applied as dopant-free hole-transporting materials (HTMs) in perovskite solar cells (PSCs). The impact of the different peripheral groups on properties of these phthalocyanines is also investigated. For the modification of bulky aroxy peripheral groups, all of the three metallophthalocyanines exhibit good solubility, suitable hole mobility, high thermal stability, and appropriate HOMO and LUMO energy levels. The most effective device based on CoPcNO2-OBFPh demonstrates an impressive power conversion efficiency (PCE) of 13.91% under AM 1.5G standard conditions, while CoPcNO2-OPMPh and CoPcNO2-OMFPh devices exhibit relative lower PCE of 11.81% and 9.47% respectively. In addition, CoPcNO2-OBFPh-based PSC shows the best stability after 1008 h in air with 50% relative humidity at room temperature.