Model ab initio study of charge carrier solvation and large polaron formation on conjugated carbon chains

Using long C(N)H(2) conjugated carbon chains with the polyynic structure as prototypical examples of one-dimensional (1D) semiconductors, we discuss self-localization of excess charge carriers into 1D large polarons in the presence of the interaction with a surrounding polar solvent. The solvation mechanism of self-trapping is different from the polaron formation due to coupling with bond-length modulations of the underlying atomic lattice well known in conjugated polymers. Model ab initio computations employing the hybrid B3LYP density functional, in conjunction with the polarizable continuum model, are carried out demonstrating the formation of both electron and hole polarons. Polarons can emerge entirely due to solvation but even larger degrees of charge localization occur when accompanied by atomic displacements.