Gas-sensing properties of PdO-modified SnO{sub}2-Fe{sub}2O{sub}3 double-layer thin-film sensor prepared by PECVD technique

摘要

The SnO{sub}2-Fe{sub}2O{sub}3 double-layer thin films have been fabricated onto silicon and ceramic substrates by using plasma-enhanced chemical vapour deposition (PECVD) technique. A small amount of PdO is coated over the surface of SnO{sub}2 thin films to improve their gas-sensing properties to CO. The surface morphologies and the structures of the oxide thin films have been investigated by means of X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) methods. Gas-sensing properties of the PdO-modified SnO{sub}2 -Fe{sub}2O{sub}3 double-layer thin film and its sensitive mechanism are discussed herein.