The tangible possibility of fabricating flexible, lightweight organic photovoltaic devices (OPVs) by using roll-to-roll coaters, similar to those used in the production of print magazines and newspapers, renders this technology a valid alternative to expensive crystalline silicon photovoltaic cells.[1–3] The most widely used active layer for these OPVs, the so-called bulk heterojunction (BHJ),[4, 5] is based on photoinduced charge transfer ...
