Organic Materials for Phovoltaics: Synthesis and Electrochemical Behaviour of a Thiophene Based Copolymer

Polymer solar cells (PSCs) have recently attracted considerable attention due to their advantages of low cost, light weight, processability and compatibility with large scale flexible substrates [1]. Polythiophenes are quite interesting materials for this purpose, combining the above described advantages with an enhanced photochemical stability, compared with poly(p-phenylene vinylene) and poly p-phenylene.In this communication the synthesis, the spectroscopic, the electrochemical and photovoltaic characterization of a thiophene based copolymerare reported. The synthesis was performed in analogy to ref. [2] via Stille coupling of a brominated and a stannilated comonomer as illustrated in Fig.1. The copolymer was characterised through 1H and 13C NMR, Uv-Vis spectroscopy, Cyclic Voltammetry.References[1] S. Gunes, H. Neugebauer, N. S. Sariciftci, “Conjugated Polymer-Based Organic Solar Cells” Chem. Rev. 107, 1324 (2007) ; M. Helgesen, R. Søndergaard, F. C. Krebs, “Advanced materials and processes for polymer solar cell devices”, J. Mater. Chem. 20, 36 (2010) ; J. Peet, J. Y. Kim, N. E. Coates, W. L. Ma, D. Moses, A. J. Heeger, G. C. Bazan, “Efficiency enhancement in low-bandgap polymer solar cells by processing with alkane dithiols”, Nat. Mater. 6, 497 (2007) ; S. A. Gevorgyan and F. C. Krebs in Handbook of thiophene-Based materials, I. F. Perepichka and D. F. Perepichka ed. (John Wiley and Sons Ltd., 2009). [2]Yongye Liang, Danqin Feng, Yue Wu, Szu-Ting Tsai, Gang Li, Claire Ray and Luping Yu, “Highly Efficient Solar Cell Polymers Developed via Fine-Tuning of Structural and Electronic Properties”, JACS 131, 7792-7799 (2009)