Organic film photovoltaic cells with gadolinium complex as an electron acceptor

A series of organic photovoltaic (PV) cells in which the electron acceptor and donor are gadolinium (dibenzoylmethanato)(3)(bathophenanthroline) [Gd(DBM)(3)bath] and N,N'-diphenyl-N,N'bis(3-methylphenyl)-1,1'-diphenyl-4,4'-diamine [TPD], respectively, Were fabricated. Although TPD acts as an active layer in the bilayered cells I insertion of a Gd-complex film between TPD and the alloy cathode is necessary for efficient carrier photogeneration. Open-circuit voltage of 3.2 V was obtained due to efficient exciton dissociation near the interface between Gd(DBM)(3)bath and TPD. By incorporating an ultrathin mixed layer of Cd-complex and TPD, external quantum efficiency is improved significantly. Photovoltaic performance of the devices has a common origin, exciplex formation, which results in broadband emission during both photoluminescent and the electroluminescent processes.