Effect of temperature on sulfur-doped diamond-like carbon films deposited by pulsed laser ablation

In this study, S-DLC films were deposited using pulsed laser ablation of a novel sulfur–graphite (SG) mixture target using an ArF excimer laser (193 nm). The SG targets were made by mixing sulfur and graphite powders at different sulfur molar percentages from 0% to 25%. The S-DLC films were deposited at room temperature, 150 °C and 250 °C. The optical and electronic properties of the doped films were studied. Laser Raman spectroscopy indicated increased graphitic behavior with temperature but decreased with higher sulfur content. Spectroscopic ellipsometry analyses found that the optical band-gap energy, extinction coefficient and reflective index, clearly depended on deposition temperature and sulfur content. Hall Effect measurements indicated n-type carrier with concentration in the range of 1 × 1014 to 2 × 1017 cm− 3, strongly depended upon the deposition temperature and amount of sulfur.

► Compressed target from mixture of pure sulfur and graphite powders.
► Pulsed laser ablation yields sulfur-doped DLC film.
► S-DLC exhibit n-type high carrier density.