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 th at for long chains the polaron forms a localized state 0.18 eV from th e band edge. Interchain coupling was described by using the results of ab initio electronic structure calculations and the actual separation s of the atoms with the closest interchain contacts. It was found that interchain coupling does not destabilize the polaron in PPV.