Measurement of electronic states in polymer by Kelvin method-effects of UV irradiation

In order to clarify the effects of UV irradiation on surface electronic states of insulating polymers, measurements of contact potential difference by the Kelvin method and of the valence band spectrum by XPS were carried out. A charge transfer range was observed at the metal-insulating polymer interface. The charge transfer range of PVK (polyvinyl carbazole) and PVP (poly-2-vinyl pyridine) was about 165 nm and 55 nm, respectively. The Fermi level of PVK became higher with UV irradiation, whereas that of PVP became lower. This Fermi level behavior is considered to be due to oxidation and morphological changes.