Inverted photovoltaic cells of nanocolumnar C60 filled with solution processed small molecule 3-Q

Nanocolumnar C-60 films for inverted organic photovoltaic cells (OPVs) were fabricated by glancing angle deposition (GLAD), and morphologies depending on variation in deposition angle were studied. To complete the OPV devices, small molecules of the donor material 3-Q were spin coated into the C-60 films. In order to avoid the difficulties of solvent stability of the C-60 films, acetone was used as the process solvent for spin coating. The nanocolumnar morphology improves exciton harvesting by increasing absorbance while providing an effective conductive path for charge carriers. The resulting GLAD C-60/3-Q devices outperformed both planar devices and PC61BM:3-Q bulk heterojunctions with threefold and two-fold short-circuit current increases, respectively. (C) 2012 Elsevier B.V. All rights reserved.