POLARONS AND THEIR STABILITY IN POLY (P-PHENYLENE VINYLENE)

We have parametrized a tight-binding description of the II electrons, with sigma bond compressibility, on a poly (p-phenylene vinylene), PPV, chain by fitting the valence band width, the band gap and the chain geometry to better than 1%. With the resulting Hamiltonian we found that for long chains the polaron forms a localized state 0.18 eV from the band edge. Interchain coupling was described by using the results of ab initio electronic structure calculations and the actual separations of the atoms with the closest interchain contacts. It was found that interchain coupling does not destabilize the polaron in PPV.