Additive effects of CuPcX4-TCNQ on CH3NH3PbI3 perovskite solar cells

Fabrication and characterization of methylammonium lead iodide CH3NH3PbI3 (MAPbI(3)) perovskite solar cells using decaphenylpentacyclosilane (DPPS), metal phthalocyanine complex doped with tetracyanoquinodimethane (TCNQ) as hole-transporting materials were performed. Additive effects of carboxylic acid, amino, or sulfonic acid sodium salt substituted phthalocyanine complex (MPcX4, M = Cu, Zn, Co, X = COOH, NH2 or SO3Na) doped with TCNQ on the photovoltaic properties, crystal orientation, morphologies and electronic structure were investigated. Incorporation of DPPS and CuPc(NH2)(4) doped with TCNQ on the perovskite layer promoted the carrier generation and charge transfer, yielding the best performance of conversion efficiency as compared with other cases. The photovoltaic performance depended on the (100) crystal orientation in the perovskite layer. The surface modification and passivation in the perovskite layer supported the photovoltaic performance with stability under air atmosphere. The molecular interaction based on overlap of pi-orbital on CuPc(NH2)(4), TCNQ and the perovskite crystal promoted the charge transfer at the interface between the perovskite layer and hole-transporting layer, improving the photovoltaic performance.