Effect of temperature on internal potential barriers in polymer-derived amorphous ceramics

The behavior of the internal potential barrier in a polymer-derived amorphous ceramic was studied by measuring its complex impedance spectra at various dc bias and temperatures. The results showed that the bias-dependent interfacial capacitance can be described by the double Schottky barrier model. Increasing temperature caused the increase in the charge-carrier concentration and decrease in the barrier height, following Arrhenius dependence. The phenomena are correlated to the electronic structure of the free-carbon phase and the amorphous matrix phase in the material.