Improving the conductivity of diamond-like carbon films with zinc doping and its material properties

Zinc doped diamond-like carbon (DLC) nanocomposite thin films are fabricated by KrF pulsed laser deposition. Carbon targets containing 3.0, 5.0 and 10.0 atomic percentages of zinc are used as the source for the laser system. Investigation of electrical properties by the four-point probe shows that doping zinc into DLC can lower the electrical sheet resistivity. Microstructural analysis by Raman spectroscopy and XPS show a lower sp3 content but a higher SiC content with an increasing amount of zinc incorporation. The increase of SiC leads to an increase in adhesion strength. Surface roughness of the films also increases while the coefficients of friction for the films do not change.

► Highly resistive diamond-like films can have a significant increase in its conductivity through the incorporation (or doping) of Zn into the amorphous film. ► Incorporation of Zn increases the critical load while maintaining similar coefficient of friction to that of pure diamond-like carbon films. ► This is the first report of Zn incorporation into diamond-like carbon films based on literature review with some unique findings. ► The growth mechanism and possible reasons were given why this phenomenon is observed for Zn but not previously observed when other metals were used.