Pretretaration Of High Barrier Hydrogenate Amorphous Carbon Film And Propertres Study

An amorphous hydrogenated carbon thin film(a-C:H film) on polyethyle-neterephthalate (PET) was fabricated by plasma-enhanced chemical vapor deposition(PECVD) with methane as the source of carbon , argon as dilution gas. The film properties were studied by XRD , XPS , FTIR , STM , AFM , Raman spectroscopy, and so on . The barrier property was examined by a water vapor permeation on the instrument designed by our laboratory according to GB-1308. As a comparison , a pure PET was tested on the standard TSY-T1 water vapor measurement instrument . The results show: the amorphous hydrogenated carbon film can be fabricated on PET surface by plasma-enhanced chemical vapor deposition. The film thickness was deposited from nm to μm range, but depending on bias voltage and power . The higher bias voltage or power , the faster deposition rate. To a certain system and parameters, the deposition rate increases with the working pressure firstly , there exists an optimum pressure , and then it rate decreases in a higer pressure. By spectrums of SEM , AFM and FTIR, it is noted an nano-amorphous hydrogenated carbon films were deposited on PET surface and the films were piled layer by layer which were composed of sp2 and sp3 hybridized hydrogenated carbon compounds, it also noticed that plasma parameters influence the property of PET stretch-resistance, but not surface energy. The barrier property of PET coated by hydrogenated carbon film is improved obviously after comparing with uncoated one, especially with a more thickness or more sp3 hydrogenated carbon component on surface.