Plasma-Enhanced CVD CeO2 nanocrystalline thin films analyzed by XPS

CeO2 nanocrystalline films were deposited on SiO2 and SiO2/Si(100) substrates by plasma enhanced-chemical vapor deposition (PE-CVD) in Ar–O2 atmospheres. Ce(dpm!4 (dpm = 2,2-6,6- tetramethyl-3,5-hept)nedionate) was used as a precursor, which allows a clean conversion into CeO2 due to the presence of Ce–O bonds. The coatings were pale yellow in color, homogeneous and crack-free. In this study, an x-ray photoelectron spectroscopy (XPS) investigation of the principal core levels (O 1s, Ce 3d) of CeO2 films was performed. The relative Ce(III)/Ce(IV) amount was estimated by evaluating the ratio of the Ce 3d3/2 (u''') satellite to the total Ce 3d integral area. The relative content of Ce(III) and Ce(IV) amount can be tailored by controlling the O2 partial pressure and substrate temperature during the depositions. The reported results represent the extension of a recently published article (Ref. 1).