Synthesis and Photovoltaic Performances of a Novel Phthalocyanine- perylene Molecular Heterojunction

A novel phthalocyanine (Pc)-perylene diimide (PDI)-Pc donor-acceptor molecular heterojunction was synthesized through amidation of an asymemetric Pc-carboxylic acid and PDI-diamines, and it is well soluble in common solvent such as dichloromethane, chloroform, and tetrahydrofuran. It shows an broad absorption band covering the whole visible region from 300 to 780 nm, and its molar extinction coefficient reaches as high as 10 L•mol•cm. Such an adsorption band originates from both the PDI and PC units. Considering the excellent light-harvesting ability, organic solar cells (OSCs) based on the synthetic compound and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) were fabricated with the configurations of ITO/poly(3,4-ethylenedioxythiophene):poly-styrenesulfonate (PEDOT:PSS)/phthalocyanine-perylene:PC61BM/Ca/Al. One of the OSC devices showed a power conversion efficiency (PCE) of 0.009% with an open-circuit voltage (Voc) of 0.472 V, a short circuit current (Jsc) of 0.104 mA/cm and a fill factor (FF) of 18.2%.