Enhancement of indium-based organic photovoltaics

We report on the optimization of poly(3-hexylthiopene) and [6,6]-phenyl C61 butyric acid methyl ester bulk heterojunction photovoltaics using indium tin oxide anode and metallic indium cathode. The devices are fabricated, tested, and stored at ambient atmosphere, without encapsulation. By tuning the spin coating conditions for the hole-transport and the photoactive layers, along with a combination of mechanical pressure and annealing conditions during the cathode deposition, a 3-fold improvement is achieved, while maintaining devices stability. Consequently, the cells undergo a less than 10% loss in power conversion efficiency after 200 days.