Abstract
The electronic structure of poly-3-hexylthiophene is studied in the solid state with photoelectron spectroscopy, as the polymer is gradually doped from NOPF6. The evolution of the core level binding energies is related to the modification of the electron density on the conjugated backbone, due to the creation of polaron and bipolaron defects. Upon doping, valence spectra show a shift in the Fermi level of the system, and at saturation doping a finite density of states is observed at the Fermi level. In the case of poly-para-phenylene vinylene, the experimental density of states of the neutral polymer is related to the results of Valence Effecttive Hamiltonian calculations. Comparison with gas phase data on styrene leads to an estimation of the polarization energy.