SPIN-DEPENDENT SELF-ASSEMBLY OF POLY(3-ALKYLTHIOPHENE) OLIGOMERS WITH AROMATIC NANOADDITIVES

Organic polymer semiconductors are promising for creating various new-generation molecular devices on their basis. Density functional theory and electron paramagnetic resonance methods were used to study the dependence of the electronic and magnetic parameters of spin charge carriers initiated in poly(3-alkylthiophene) oligomers on their structure and conformation. The localization of some carriers was identified due to the specificity of their formation, relaxation, and interaction with their microenvironment. An exponential narrowing of the oligomer band gap with an increase in the degree of its polymerization was found. Anisotropic parameters of spin Hamiltonians of the studied systems were obtained and their high-resolution EPR spectra were calculated.

The relationship between the electronic and spin properties of oligomer composites and the molecular structure of polyaromatic additives with an extended π-structure was established. The periodicity of changes in these properties caused by the interaction of polaron spins with the π-electron structure of nanoadditives was discovered for the first time. The possibility of controlled self-assembly of oligomer complexes with the introduction of polyaromatic hydrocarbon additives was shown. The formation of completely organic spinterfaces is accompanied by a decrease in the torsion angle between the monomers, spatial orientation and convergence of oligomer chains, enhancing the hyperfine interaction of charge carrier spins with their microenvironment and accelerating their intra- and interchain mobility. This opens up new horizons for the controlled functionality of polymer molecular devices with spin-dependent electronic properties.