[0002] Photovoltaic (PV) systems convert electromagnetic energy into electrical energy. Photovoltaic systems can be categorized based on the architecture of the devices and the materials of construction. Organic photovoltaic systems comprise an organic photoelectric active material. The organic photoelectric active material typically comprises a semiconducting organic polymer and a fullerene compound. When the semiconducting organic polymer comes into contact with incident light in or near the visible part of the electromagnetic spectrum, delocalized π electrons are excited by the electromagnetic energy from the polymer molecule's highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO).