Khlaifia, D., Ewels, C. P., Massuyeau, F., Chemek, M., Faulques, E., Duvail, J.-L. & Alimi, K. (2016) Unraveling the real structures of solution-based and surface-bound poly(3-hexylthiophene) (P3HT) oligomers: a combined theoretical and experimental study. RSC Adv. 6 56174–56182.
Added by: Richard Baschera (2016-07-15 09:27:10) Last edited by: Richard Baschera (2016-07-15 09:30:13)
|Type de référence: Article
Numéro d'identification (ISBN etc.): 2046-2069
Clé BibTeX: Khlaifia2016
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|Catégories: INTERNATIONAL, MIOPS, PMN
Mots-clés: Band-gap, conjugated polymers, density-functional theory, electronic-properties, head-to-tail, optical-properties, organic solar-cells, side-chains, single-crystals, torsional potentials
Créateurs: Alimi, Chemek, Duvail, Ewels, Faulques, Khlaifia, Massuyeau
Collection: RSC Adv.
Consultations : 7/659
Indice de consultation : 4%
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While the crystalline structure for regio-regular poly(3-hexylthiophene) (P3HT) in thin films is well established, the conformation of P3HT chains in solution has received less attention. Nevertheless, the control of this in-solution structure can be used for managing the structure-processing relationship, which can be used to improve the optoelectronic behavior and thus the efficiency of devices exploiting electroactive polymers. In the current study, we report a combined theoretical and experimental study of P3HT and a series of oligomers, both in the solid state and in solution. (3HT)(n) oligomers were simulated in a variety of planar and non-planar conformations by means of density functional theory (DFT) and time-dependent DFT (TDDFT), comparing results for various functionals with and without dispersion correction in order to evaluate the role of intermediate and long-range effects. Our calculations show that regio-regular P3HT chains adopt a twisted conformation in solution (dihedral angle of about 40 degrees), which contrasts with the well-established planar (theta = 0 degrees) conformation when deposited onto a substrate, due to inter-chain interactions. Determining the Raman spectra, electronic gaps, quasi-particle energies and optical spectra, a good agreement between experimental and simulated optical absorption spectra was obtained for the in-solution case. This study will help to promote the development of alternative strategies for controlling the optoelectronic features of conjugated polymers and polymer blends by exploiting the in-solution structure.