Electrochemical Impedance Spectroscopy Studies of HF CVD Diamond Films

Abstract

Diamond lms were synthesized by a hot lament vapor deposition method using H2/CH4 gas mixtures. A Hioki impedance analyzer was used to study the dielectric properties of the deposited diamond lms. The dielectric dispersion measurement yielded the real and imaginary parts of impedance of diamond lms in the form of a Nyquist plot in a complex plane. The obtained results were tted by using equivalent circuit which consists of three impedance (Z) components containing resistor R and capacitor C or constant phase element connected in parallel. The structure and quality of diamond lms were analyzed by scanning electron microscopy and the Raman spectroscopy. The impedance measurements showed that concentration of non-diamond admixture has essential inuence on electrochemical properties of diamond layers.