Papers by Keyword: Silicon Coating

Abstract: In the present work, the light-emitting property of silicon coating was explored and the related morphologies and chemical structure of silicon coating were characterized. Silicon coating was prepared by vacuum plasma spray technique and chemically treated by HNO₃/HF vapor. The coatings before and after the vapor etching were characterized by field emission scanning electron microscopy and micro-raman spectroscopy. The photoluminescence spectra of the silicon coatings treated with different time were examined. It is found that pores of micrometer and microcracks formed on the surface of silicon coatings after the treatment. The treated silicon coatings exhibited room temperature visible photoluminescence with emission wavelength around 650 nm after excitation. The results of micro-raman measurement proved that there were polysilane and oxygen related functional groups appeared on the coating surface after the vapor treatment, which was supposed to be responsible for the photoluminescent phenomena.

Abstract: Silicon-based materials have been widely applied in industrial fields, such as microelectronic and solar power, for the specific electronic properties. In the present work, free-standing thick silicon coatings were fabricated by air plasma spraying (APS) and vacuum plasma spraying (VPS) technologies. The microstructure and electrical property of the coatings were characterized. It was found that the electrical resistance of APS-Si coating was higher than that of VPS-Si coating. The impedance spectroscopy results showed there was significant difference in impedance curves of APS-Si and VPS-Si coatings. The grain boundary semicircle appeared in the plot of VPS-Si coating, while did not appeared in that of APS-Si coating. It was thought that the electrical property difference of the two kind coatings was related with the oxidation and microstructure difference of the coatings.

Abstract: The main goal of the present study was to determine the surface features, surface failures and fatigue properties of coated coronary stents. The quality and the changing of the coatings were examined by different methods. In this paper, the results of the examinations with different coated coronary stents are introduced and the results of the coating experiments are shown as well.

Abstract: In this work, silicon coatings were deposited using VPS and APS technologies. Their structure and composition were characterized using XPS, SEM, and XRD. The porosity and surface-roughness of coatings were evaluated. The results showed that the VPS silicon coating possessed lower porosity compared with the APS silicon coating. The APS silicon coating surface was almost all covered by many small particles whose size is about 100 nm. The Si 2p XPS spectra indicated that silicon oxide existed in both coatings. The oxidation may have occurred during the plasma spray process. However, the VPS process could inhibit silicon from being oxidated.