Electrochemical impedance in H2SO4 solutions and the kinetics of redox reactions in the Fe(CN)(6)(3-/4-) system were studied in amorphous nitrogenated diamond-like carbon thin-film electrodes. The films were fabricated on p- and i-type silicon and quartz substrates, using direct ion beam deposition from an RF inductively coupled N-2 + CH4 plasma source. The films were characterized by optical and electrical measurements. Parameters of point defects (trapping centres) were measured by deep level transient spectroscopy techniques. The increase in the N-2/CH4 ratio in the gas mixture leads to a decrease in the electrical resistivity and optical bandgap of the films from 3 x 10(10) to 5 x 10(6) 92 cm and from 1.3 to 0.6 eV, respectively. Simultaneously, the concentration of electrically active point defects increased and the charge transfer at the a-C:N:H film I redox electrolyte interface was significantly facilitated.