The mechanism of schottky-barrier formation in poly-p-phenylene

The temperature dependence of the capacitance and current-voltage characteristics of Al/PPP junction device has been measured in order to investigate the junction properties. The barrier height and the effective Richardson constant of the junction have been determined to be 0.48 eV and 1.2x1/sup -4/Acm/sup -2/K/sup -1/ by Richardson plots. Analysis of the metal-polymer interface by x-ray photoemission spectroscopy (XPS) technique shows that an aluminum oxide complex is formed at the interface which would be the origin of the contact effects. The small effective Richardson constant has been due to existence of that composite layer, acting as a tunneling one.