Organic photovoltaic devices (OPVs) hold promise for a variety of applications requiring alternative energy generation. Through a collaboration betweenÂ’ Northwestern University MRSEC IRG 4 and Wright Patterson Air Force Base, a new strategy for characterizing the electrical and optical performance of operating OPVs has recently been developed. Atomic force photovoltaic microscopy allows the photocurrent response in OPVs and other optoelectronically-active materials and devices to be spatially mapped down to the nanometer length scale. Atomic force photovoltaic microscopy image of the short circuit response of an array of illuminated organic solar cells.