Efficiency enhancement of organic photovoltaic devices using a Sm:Al compound electrode

An effective cathode consisting of samarium (Sm) doped aluminum (Al) layer and a pure Al layer is reported for application in organic photovoltaic cells (OPVs). Standard copper phthalocyanine (CuPc)/C₆₀ OPVs using this bilayer cathode show dramatically increased short-circuit current density and power conversion efficiency, which are 64% increased by employing a appropriate ratio of 1:3 of Sm:Al layer as compared with that of control devices with pure Al cathode. The photoelectric properties reveal that the improved efficiency is mainly related to the balance of the enhanced electron collection ability and the optimized optical reflection of a Sm doped Al layer.