Solution-Processed\nHybrid Cathode Interlayer for Inverted Organic Solar Cells

Abstract

A novel hybrid material CdS/2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline\n(CdS·BCP) was prepared from the decomposition of its organic\nsoluble precursor complex Cd­(S₂COEt)₂·(BCP)\nby low-temperature treatment. CdS·BCP, which integrated the favorable\nproperties of solvent durability, and high electron mobility of CdS\nas well as the good hole blocking property of BCP, was designed and\ndeveloped as the interface modification material to improve electron\ncollection in bulk heterojunction organic solar cells (OSCs). The\ninverted OSCs with CdS·BCP as buffer layer on ITO showed improved\nefficiency compared with the pure CdS or BCP. Devices with CdS·BCP\nas interlayer exhibited excellent stability, only 14.19% decay of\npower conversion efficiencies (PCEs) was observed (from 7.47% to 6.41%)\nafter stored in glovebox for 3264 h (136 days). Our results demonstrate\npromising potentials of hybrid materials as the interface modification\nlayers in OSCs, and provide new insights for the development of new\ninterface modification materials in the future.