Diamond Like Carbon Films Containing Si: Structure and Nonlinear Optical Properties.

Šarūnas Meškinis,Andrius Vasiliauskas,Karolis Viskontas,Sigitas Tamulevičius,Domantas Peckus,Mindaugas Andrulevičius

doi:10.3390/ma13041003

Šarūnas Meškinis, Andrius Vasiliauskas + Show 4 more

Open Access

https://doi.org/10.3390/ma13041003

Copy DOI

Journal: Materials	Publication Date: Feb 23, 2020
Citations: 79	License type: CC BY 4.0

Affiliation: Kaunas University of Technology, Ekspla (Lithuania)

Abstract

In the present research diamond-like carbon (DLC) films containing 4–29 at.% of silicon were deposited by reactive magnetron sputtering of carbon target. Study by X-ray photoelectron spectroscopy revealed the presence of Si–C bonds in the films. Nevertheless, a significant amount of Si–O–C and Si–Ox bonds was present too. The shape of the Raman scattering spectra of all studied diamond-like carbon containing silicon (DLC:Si) films was typical for diamond-like carbon. However, some peculiarities related to silicon doping were found. Studies on the dependence of DLC:Si of the optical transmittance spectra on the Si atomic concentration have shown that doping by silicon affects linear, as well as nonlinear, optical properties of the films. It is shown that the normalized reflectance of DLC:Si films decreased with the increased exciting light fluence. No clear relation between the normalized reflectance and photoexcited charge carrier relaxation time was found. It was suggested that that the normalized reflectance decrease with fluence can be related to nonlinear optical properties of the hydrogenated diamond-like carbon phase in DLC:Si film.

Highlights

Diamond-like carbon (DLC) is a metastable form of amorphous carbon and can be considered as some kind of nanocomposite, where sp2 bonded carbon nanoclusters are embedded into the sp3 bonded carbon matrix
diamond-like carbon (DLC):Si films containing 4–29 at.% of silicon were deposited by reactive magnetron sputtering
The shape of the Raman scattering spectra of all studied DLC:Si films was typical for diamond-like carbon and significant nearly-linear downshift of the G peak position with the increased Si atomic concentration was found

Summary

Introduction

Diamond-like carbon (DLC) is a metastable form of amorphous carbon and can be considered as some kind of nanocomposite, where sp bonded (graphite-like) carbon nanoclusters are embedded into the sp bonded (diamond-like) carbon matrix. Diamond-like carbon films are under considerable interest due to a very interesting combination of the high hardness, low friction coefficient, wear and corrosion resistance, and biocompatibility [1,2,3,4,5,6]. Properties of DLC films can be controlled by introducing chemical elements other than carbon or hydrogen [1,3,4,5,6,7,8]. Reduced internal stress and friction coefficient, as well as increased thermal resistance, while keeping high hardness of Si doped diamond-like carbon films were reported [9]. Silicon doping of DLC films resulted in reduced internal stress, increased hardness, and improved high-temperature tribological properties [15]. It was shown that friction coefficient of DLC:Si films in ambient air was lower than the friction coefficient of the Materials 2020, 13, 1003; doi:10.3390/ma13041003 www.mdpi.com/journal/materials

Methods

Results

Conclusion