Structure-property relationships of soluble poly(2,5-dibutoxyethoxy-1,4-phenylene-alt-2,5-thienylene) (PBuPT) for organic-optoelectronic devices

In this work, we have analyzed the vibrational, optical and emission properties of soluble copolymer denoted poly(2,5-di-butoxyethoxy-1,4-phenylene-alt-2,5-thienylene) (PBuPT) by combining experimental and theoretical studies. Extrapolated Ionization Potentials (IPs), Electron Affinities (EAs) and energy gaps were determined employing Density Functional Theory (OFF) method. Theoretical analyses have been performed in order to understand deeply the interesting role played by the intra-molecular S center dot center dot center dot O interactions in determining the planarity of the copolymer. Further, an intra-molecular charge transfer for the copolymer has been proposed through the alternating donor-acceptor conjugated systems. In addition, vibrational, optical and emission spectra of three repeat units model compound have been simulated and compared to the experiments. Based on these results, we have described attentively the structure-property relationships of those samples which could be exploited as an active layer in organic optoelectronic devices. (c) 2012 Elsevier B.V. All rights reserved.