Light-Emitting Characterization of Vacuum Plasma Sprayed Silicon Coatings

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.