Green Energy

Biography

Biography: Sausan Al-Riyami

Abstract

Ultrananocrystalline diamond/hydrogenated amorphous carbon (UNCD/a-C:H) films commonly prepared by chmical vapour depositon (CVD) technique. Although it can be grown in an atmosphere including no hydrogen gas, the hydrogen from a hydrocarbon source gas can infulance the properties of the film. The hydrogen has important roles on the physical properties of the films; however it has never been studied in details thus far. We have reported that nonhydrogenated amorphous carbon (a-C) films containing no diamond grains are grown without ambient gas by pulsed laser deposition (PLD). On the other hand, in this work the growth of film. The chemical bonding structures, the electrical, and the optical properties of the films were investigated in details using several technigues. The films were deposited on silicon and quartz substrates in hydrogen atmospheres by PLD using a graphite target. The preparation conditions were similar to those in our previous works. The films were studied using several techniques. The carrier density was calculated using electron spin resonance (ESR). For the first to our knowledge non-commercial standard sample was prepared and used to calibrate and quantify the measurements. The standard sample shows a strong stability and it is considered to be competitive to the commercial samples. The ESR investigation was performed at different temperatures. The estimated spin density is relatively high for an insulator UNCD/a-C:H composite film. From the obtained results it is found that ESR is a promising method to study paramagnetic canters and their interaction with hydrogen for films.