Effects of Postproduction Treatment on Plastic Solar Cells

Abstract Efficiencies of organic solar cells based on an interpenetrating network of a conjugated polymer and a fullerene as donor and acceptor materials still need to be improved for commercial use. We have developed a postproduction treatment that improves the performance of solar cells based on poly(3‐hexylthiophene) (P3HT) and [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) by means of a tempering cycle at elevated temperatures in which an external voltage is simultaneously applied, resulting in a significant increase of the short‐circuit current. Using this postproduction treatment, an enhancement of the short‐circuit current density, Isc, to 8.5 mA cm–2 under illumination with white light at an illumination intensity of 800 W m–2 and an increase in external quantum efficiency (IPCE, incident photon to collected electron efficiency) to 70 % are demonstrated.