Effect of tungsten doping on laser ablation and graphitization of diamond-like nanocomposite films. (March 2021)

• Record Type: Journal Article
• Authors: Komlenok, M.S.; Arutyunyan, N.R.; Freitag, C.; Zavedeev, E.V.; Barinov, A.D.; Shupegin, M.L.; Pimenov, S.M.
• Is Part Of: Optics & laser technology. Volume 135(2021)
• Publication Date: 2021-03
• Subjects: DLN film -- Tungsten doping -- Laser ablation -- Laser-induced graphitization -- Raman spectroscopy; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2020.106683
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Wavelength-dependent laser processing of DLN (a-C:H:Si:O) and metal-doped DLN films. W-doping has opposite effect on ablation rate/threshold for UV ns- and IR ps-pulses. Laser-induced graphitization is stronger for metal-doped DLN films in most cases. Graphitized layer thickness is ~4 nm after IR ps-laser processing of undoped films. Abstract: Laser surface microstructuring of diamond-like nanocomposite (DLN) films is a promising technique to improve their properties. For industrial applications, UV excimer or IR lasers with high pulse repetition rate are commonly used. In this paper, we investigate the influence of metal (tungsten) doping of DLN film on the ablation and graphitization behavior of the films using KrF laser (λ = 248 nm, τ = 20 ns) and Yb:Yag laser (λ = 1030 nm, τ = 8 ps). The response is found to be sensitive to the laser wavelength and pulse duration. For UV ns-pulses, the ablation threshold is insensitive to W-doping, showing only a slight increase for the highest tungsten concentration of 27 at.%, while the ablation rate decreases. Conversely, an increase of tungsten content in the case of the irradiation by IR ps-pulses induces a drop in the ablation threshold and an increase in the ablation rate. The structural modification of the films is analyzed by Raman spectroscopy, which also allows us to estimate the thickness of a residual graphitized layer on the surface after laser irradiation. It is found that laser-induced graphitization is stronger for doped DLN films after multipulse irradiation.