Optical and electrical properties of fullerene C70 for solar cell applications

• Published in: Optical materials Vol. 101; p. 109717
• Main Authors: Sachdeva, Sheenam, Singh, Devinder, Tripathi, S.K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2020
• Subjects: Defects; Electrical properties; Fullerenes; Optical properties; Vapor deposition; Fullerenes; Vapor deposition; Electrical properties; Optical properties; Defects
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2020.109717

This research paper demonstrates the successful deposition of fullerene C70 for application as an acceptor material in Schottky barrier organic solar cell (OSC) device with structure fluorine-doped-tin-oxide/molybdenumtrioxide/fullerene/lithiumfluoride/aluminium (FTO/MoO3/C70/LiF/Al) using vapor thermal deposition technique. Morphology analysis using field emission scanning electron microscopy (FESEM) shows the mesoporous nature of highly cross-linked C70 molecules in deposited C70 thin film. But more uniform C70 film with less porosity has been deposited with high evaporation rate. We report the optical and electrical characterizations which reveal the thin film to be useful in photovoltaic applications. To study optical absorption spectra over visible energy range, prepared samples have been characterized by ultraviolet–visible (UV–vis) absorption spectroscopy. Optical dielectric parameters and dispersion properties of samples are studied. Constant Photocurrent Method (CPM) is employed to measure the mid gap absorption spectra of fabricated device. Defect density of states (DOS) distribution, Urbach energy and steepness parameter are also evaluated. Current-voltage characteristics of device in dark as well as under illumination surmise the behavior of device similar as Schottky barrier OSC.
•Fabrication of fullerene based organic solar cell using vapor thermal deposition technique.•Consistency of fabricated device as a Schottky barrier solar cell.•Evaluation of optical constants and dispersive properties of device.•Determination of defect density of states distribution in mid gap region by constant photocurrent method.