Top light-harvesting organic solar cell using ultrathin Ag/MgAg layer as anode

We fabricate a top light-harvesting organic solar cell (TL-OSC) with a Si substrate/SiO2 layer/cathode/organic layer/semitransparent metal anode structure. We obtain power conversion efficiency (eta(p)) comparable to that of conventional bottom-type OSCs. To harvest light from a top anode, we use a 1 nm Ag layer/4 nm MgAg layer having a transmittance of 55 - 80% in the visible and near-infrared regions. We also insert an ultrathin molybdenum oxide (MoO3) layer at the cathode/organic layer interface to increase hole collection efficiency from the organic layer into the cathode.