Influence of chemical structure of α-C∶H films on optics property

α-C∶H thin films were deposited by low-pressure plasma chemical vapor deposition(LPPCVD) with H2 (99.999 9%) and Trans-2-butene as source gases. The chemical bonds and electronic structure are analyzed by using FTIR and XPS. The ratio of sp3/sp2 and the percentage of sp3 C are also analyzed by using the fitting of Gaussian peak fitting. The results show that the chemical structure and composition of the films change with the pressure, and this films mainly contain sp3C—H bond, which have low pressure and possess less C=C bonds. When the pressure increases, the sp3/sp2 hybrid ratios and the percentage of sp3 bonds increase. The optical properties of a-C∶H films are investigated by UV-VIS spectrum in the range of 400~1 100 nm. The transmission ratios can reach 98% in the visible light