Interchain interactions in polyacetylene: Optical properties and photoconductive response

Abstract

A simple tight-binding model extended to include the zig-zag structure of the chains and the interchain electronic coupling has been used to account for the dispersion of the real and imaginary part of the dielectric function of polyacetylene as derived from optical measurements. The model also accounts for the pump polarization anisotropy observed in the photoexcitation of oriented trans-(CH${)}_{\mathit{x}}$. It is established that a relatively small hopping integral (${\mathrm{\ensuremath{\beta}}}_{\mathrm{\ensuremath{\perp}}}$\ensuremath{\simeq}0.05 eV), combined with laser heating effects, accounts for the observed experimental features, assuming that bimolecular recombination does not occur.