Marchiori Cleber F N, Garcia-Basabe Yunier, de A Ribeiro Fabio, Koehler Marlus, Roman Lucimara S, Rocco Maria Luiza M
Department of Physics, Federal University of Paraná, Curitiba 81531-990, Brazil.
Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro 21941-909, Brazil.
Spectrochim Acta A Mol Biomol Spectrosc. 2017 Jan 15;171:376-382. doi: 10.1016/j.saa.2016.08.010. Epub 2016 Aug 9.
We use X-ray photoelectron spectroscopy (XPS), Near-edge X-ray absorption fine structure (NEXAFS), resonant Auger spectroscopy (RAS), Attenuation Total Reflection Infrared (ATR-IR) and Atomic Force Microscopy (AFM) to study the blend between the copolymer poly[2,7-(9,9-bis(2-ethylhexyl)-dibenzosilole)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole] (PSiF-DBT) and the fullerene derivative PCBM submitted to different annealing temperatures. Those measurements indicate that there is an incidental anchoring of a fullerene derivative to the Si-bridging atoms of a copolymer induced by thermal annealing of the film. Insights about the physical properties of one possible PSiF-DBT/PCBM anchored structure are obtained using Density Functional Theory calculations. Since the performance of organic photovoltaic based on polymer-fullerene blends depends on the chemical structure of the blend components, the anchoring effect might affect the photovoltaic properties of those devices.
