Interface characteristics of polymer-derived amorphous SiCN ceramics investigated by impedance spectroscopy under direct current bias

Abstract

The interface characteristics of polymer derived ceramics determine their dielectric properties, useful for sensing applications. In this contribution, the interface characteristics of polymer-derived amorphous SiCN ceramics were studied using direct current (dc) bias superimposed on alternating current (ac) impedance spectroscopy. Double Schottky barrier model was applied to determine the interface characteristics. Potential height and donor concentration at the interface were estimated to 0.99eV and 2.91 × 1018cm−3, respectively. Interface density was recorded as 2.69 × 1013cm−2. Interface resistance reduced as bias rose, resulting in increased dielectric loss. Interface capacitance also declined as bias increased, thus reducing dielectric constant. These changes were related to potential barrier height and width of barrier region. Overall, these findings look promising and should benefit further understanding on interfacial polarization processes of polymer-derived ceramics.