On accurate capacitance characterization of organic photovoltaic cells

Capacitance measurements, widely used to characterize numerous semiconductor properties, have been recently adopted to characterize organic photovoltaic (OPV) devices. It is known that certain challenges are associated with capacitance measurements. Of upmost importance is the employment of a proper measurement model (series or parallel). Owing to larger capacitive impedances and low series resistances, the parallel model is typically employed in inorganics. However, we find that for characteristically thinner organic films, a hybrid model should be used. We highlight the inconsistencies in OPV literature due to indiscriminate usage of parallel model and show how proper model selection can rectify any artifacts. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4720403]