Surface electronic structure and molecular orientation of poly(9-vinylcarbazole) thin film:: ARUPS and NEXAFS

The molecular orientation at the surfaces of poly(9-vinylcarbazole) (PvCz) thin films was studied by angle-resolved ultraviolet photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The observed take-off angle (θ) dependence of photoelectron intensities from top π band peaks clearly at larger θ than the calculated one for the three-dimensional isotropic random orientation model. The results indicate that there are more pendant groups with large tilt angles than the three-dimensional isotropic random orientation model, which is in good agreement with the result obtained from NEXAFS spectroscopy. The surface electronic states of PvCz may be rather dominated by σ(C–H) states at the pendant carbazole group than π states