Synthesis of DLC films with different sp²/sp³ratios and their hydrophobic behaviour

Abstract

Diamond-like carbon (DLC) films were deposited on glass substrate by sputtering of a vitreous carbon target in Ar + H2 plasma. The sp2/sp3 content in the films depended on the relative amount of hydrogen in the Ar + H2 plasma. The films were characterized by Fourier transformed infrared studies, Raman studies, scanning electron microscopy, atomic force microscopy and optical measurements. Hydrophobicity in these films was studied by measuring the contact angles of the water droplets and it was found that the films were extremely hydrophobic. The results are interpreted in terms of hybridization of carbon in these DLC films.

Flexible diamond-like carbon film prepared by hydrothermal electrochemical method

“…5 shows the Raman spectra of the deposited DLC films. The observed G and D peaks in the four kinds of the films reveal the existence of both sp2-type and sp3-type carbon bonding in the DLC films [14]. By fitting procedures, the intensity ratio of D band to G band (I D /I G ) for samples a, b, c, and d has been found to be about 0.66, 1.38, 1.96 and 3.2, respectively.…”

Influence of torch power and Ar/C2H2ratio on structure of amorphous carbon films

“…The I D /I G ratio increases from 1.82 to 2.41 with increase of the argon-acetylene ratio from 100 to 200. Thus, the D (1410 cm −1 ) and G (1617 cm −1 ) bands are shifted to higher wave number range, compared to the typical D and G peaks [8,17]. This is related to high internal stresses in the coating.…”

“…Meanwhile, the coating produced at Ar/C 2 H 2 = 150, beside D (1386 cm −1 ) and G (1610 cm −1 ) peaks, has a narrow band at 1447 cm −1 . This peak is attributed to a C5 A g (2) pentagonal pinch mode or due to relaxation of the photon selection rules for nanocrystalline materials [17,18]. The film deposited at the highest Ar/C 2 H 2 ratio has only D and G peaks centred at 1382 and 1609 cm −1 , respectively.…”

“…The same tendency was obtained for the FWHM of the G band (increases from 74 to 86 cm −1 ). Paul et al [17] have proposed that the FWHM of the G peak would be small if the clusters were defect free, unstrained, or molecular. Thus, the broader FWHM would mean higher bond length and bond angle disorder and hence higher fraction of the sp 3 sites.…”

Dual-Frequency Plasma Enhanced Chemical Vapor Deposition of Diamond-Like Carbon Thin Films

“…The structure of DLC lm is a mixture of some graphitic sp 2 and aliphatic sp 3 bonding and the fraction ratio of them (sp 3 /sp 2 ) strongly ascertains the physical properties of it. In general, although the mechanical and chemical characteristics are governed by amount of the sp 3 bonding, electronic and optical properties are associated to fraction of the sp 2 bonding [5,6]. Therefore, it is essential to have precise control on the fraction ratio to deposit a favorite layer relevance to the applications.…”