Effect of nickel incorporation on microstructural and optical properties of electrodeposited diamond like carbon (DLC) thin films

A simple electrodeposition technique was used to synthesize diamond like carbon (DLC) and nickel incorporated diamond like carbon (Ni-DLC) thin films on ITO coated glass substrates. Initial concentration of nickel in the electrolyte was kept fixed at 4.76 x 10(-4) M for all depositions of Ni-DLC films. Growth process of the films was studied by synthesizing films with variation of deposition time. With nickel addition to DLC the band gap and the Urbach energy varied from 2.67 eV to 2.48 eV and 1.0803 eV to 1.452 eV, respectively as estimated from UV-vis-NIR spectrophotometry of DLC and Ni-DLC. Results indicated that the metal incorporation effectively increased the graphitization of DLC films. Microstructural studies by SEM and AFM revealed that the particles in the Ni-DLC films were evenly distributed and the packing density of particles increased with increased time of deposition. XRD pattern exhibited the presence of Ni crystallites in an amorphous carbon network along with the phases of diamond and graphite in the Ni-DLC film. The FTIR spectrum showed peaks accountable for both CH3 and CH2 bonding. It was also apparent that nickel incorporation significantly modulated the FTIR spectrum of DLC film, as several new peaks appeared only in the case of Ni-DLC film at similar to 776 cm(-1), 745 cm(-1) and 668 cm(-1). (C) 2012 Elsevier B. V. All rights reserved.