Synthesis and properties of polydiphenylsilane/fullerene C60 nanocomposites

The efficiency of bulk heterojunction solar cells based on polysilane/C-60 nanocomposites could be improved by delaying the radiative recombination of the charge carriers using aromatic side groups as mediators. This paper presents a study of such nanocomposites prepared with a soluble polydiphenylsilane, a polymer that contains a high number of phenyl groups attached to the main chain. Synthesis of this polysilane is challenging and was done by microwave-assisted Wurtz coupling of diphenyldichlorosilanes in the presence of low amounts of methyldichlorosilane. The nanocomposites were obtained in solution by mixing the polymer with C-60 of various concentrations. The UV-vis profile shows formation of the intermolecular charge transfer complex between polysilane and C-60 which acts as a dopant Photoluminescence experiments at different concentrations of C-60 revealed details concerning the emission from charge transfer states at the interface. Thin films of polysilane/C-60 nanocomposites were casted from solutions and studied by AFM and TEM to evidence the main aspects of their microstructure. The obtained results confirmed the high potential of these materials for electro-optical devices. (C) 2014 Elsevier B.V. All rights reserved.