Photovoltaic cells from a soluble pentacene derivative

Multilayer heterojunction photovoltaic cells were fabricated using a solution processable pentacene derivative as the donor layer. Upon annealing of these devices, the open circuit voltage was found to gradually increase with temperature up to 265 °C. Further improvement in the photovoltaic performance was achieved with the incorporation of mobile ions into the donor material for concentrations of lithium triflate up to 1.4 mg/ml. Finally, after introducing an exciton blocking layer, an optimized white-light (100 mW/cm2) power conversion efficiency of 0.52% was achieved.