SYNTHETIC SEMICONDUCTOR DIAMOND ELECTRODES - THE COMPARATIVE-STUDY OFTHE ELECTROCHEMICAL-BEHAVIOR OF POLYCRYSTALLINE AND SINGLE-CRYSTAL BORON-DOPED FILMS

Capacitance and potentiodynamic measurements were conducted on single crystal (homoepitaxial) and polycrystalline boron-doped diamond thin-f ilm electrodes. The impedance characteristics and kinetic data in the Ce3+/4+ redox system, even if having a great deal of variability, appe ared to be similar for the two kinds of diamond electrodes, whereas th e kinetics of redox reactions on crystalline diamond and amorphous dia mond-like carbon films differ significantly. These data in aggregate l ead to a tentative conclusion that the electrochemical behaviour of po lycrystalline diamond is determined by the diamond crystallites proper , rather than by the disordered carbon of the intercrystallite boundar ies. The concentration of uncompensated accepters in diamond was estim ated from the linear and non-linear impedance data. The ways of presen tation of Mott-Schottky plots for semiconductor electrodes are discuss ed for the case of frequency-dependent differential capacitance. (C) 1 998 Elsevier Science S.A. All rights reserved.