Preparation and characterization of close-packed nanostructured sol-gel ceria thin films prepared using cerium-sec-butoxide as precursor

作者：Ferrara Maria Cristina^*; Piscopiello Emanuela; Laera Anna M; Pilloni L; Mazzarelli S; Tapfer L

来源：Journal of Sol-Gel Science and Technology, 2011, 60(3): 333-339.

DOI：10.1007/s10971-011-2529-1

• Ceria
• Ceria-alkoxide
• Nanostructured thin films
• Complex refractive index
• Energy gap

Polycrystalline, close-packed, homogeneous nanostructured ceria thin films were prepared by sol-gel process via dip-coating technique on soda-lime glass and (100)-oriented Si substrates. To produce the films, a sol was prepared using, as precursor, a home made cerium sec-butoxide dissolved in secondary butanol. The chemical composition, the microstructural/morphological characteristics and the optical properties of the coatings were investigated in detail. The experimental results clearly demonstrate that the ceria films are nanocrystalline (CeO(2), cubic phase Fm (3) over barm) with an average grain size of about 2-3 nm for the samples grown on glass and of about 4-5 nm for the samples grown on silicon. The analyses of ceria layers grown on silicon show that the ceria coatings are free from organic residues and that a Si-oxide layer is formed at the film/substrate interface. The optical results evidence a red shift of the energy gap of about 0.5 eV that can be ascribed to conversion of relevant Ce(4+) sites to Ce(3+) sites and a consequent creation of oxygen vacancy at the surface of the ceria grains.

• 出版日期2011-12