DFT and EPR study of spin-assisted processes in poly(3-alkylthiophene) oligomers and their composites

Abstract

Correlations of spin, electronic and magnetic resonance parameters of charge carriers stabilized in poly(3-alkylthiophene) oligomers with their band structure, polymerization degree, side substitutes, and conformation established by using the density functional theory and electron paramagnetic resonance methods. The comparison of calculated and experimental data identified spin distribution on oligomer chains with different conformations. The type and size of alkyl substituent of polymer matrix governs the band gap, mobility, and spin-orbit coupling of polaron charge carriers. The introduce of small aromatic additives between oligomer chains initiates their self-assembly crystallization and formation of organic:organic spinterfase which accelerate spin-assisted electronic and magnetic processes in the composite. The research revealed that embedding aromatic hydrocarbons into oligomer bulk allows continuous and discrete handling of electronic spin-assisted processes carrying out in respective organic/organic composites. The key role of spinterfacial effects in the development of a new generation of molecular devices with actively tuned spin-assisted functionality is described.