Authors: Raad A. Alawajji, Ganesh K. Kannarpady, Zeid A. Nima, Nigel Kelly, Fumiya Watanabe, Alexandru S. Biris
Publication: Applied Surface Science, Volume 437, 15 April 2018, Pages 429-440
In this work, pulsed laser deposition was used to produce a multilayer (ML (DLC-TiC)) thin film. The ML (DLC-TiC) films were deposited on Si (100) and glass substrates at various substrate temperatures in the range of 20–450 °C. Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), and atomic force microscopy were utilized to characterize the prepared films. Raman analysis revealed that as the substrate temperature increased, the G-peak position shifted to a higher wavenumber and the full width at half maximum of the G and D bands decreased. XPS analysis indicated a decrease in sp³/sp² ratio and an increase in Ti-C bond intensity when the substrate temperature was increased. Additionally, the surface roughness of ML (DLC-TiC) films is affected by the type and temperature of the substrate. The electrical measurement results indicated that the electrical resistivity of the ML (DLC-TiC) film deposited on Si and glass substrates showed the same behavior—the resistivity decreased when substrate temperature increased. Furthermore, the ML (DLC-TiC) films deposited on silicon showed lower electrical resistivity, dropping from 8.39E–4 Ω-cm to 5.00E–4 Ω-cm, and the films on the glass substrate displayed a drop in electrical resistivity from 1.8E–2 Ω-cm to 1.2E–3 Ω-cm. These enhanced electrical properties indicate that the ML (DLC-TiC) films have widespread potential as transducer for biosensors in biological research; electrochemical electrodes, because these films can be chemically modified; biocompatible coatings for medicals tools; and more.