Influence of Surface Recombination on Charge-Carrier Kinetics in Organic Bulk Heterojunction Solar Cells with Nickel Oxide Interlayers

Organic solar cells have many merits, including low cost and the ability to cover large and flexible substrates, yet there is much room to improve them. To maximize their efficiency, this study investigates the effects of surface recombination in a model system, in which the work function of electrode contacts is varied via oxygen-plasma treatment. The authors explain how changing the properties of the contact has a profound effect not only on device efficiency, but also on the interpretation of optoelectronic measurements of these devices.