Resumo

LOPEZ, R. et al. Caracterización estructural y óptica de compósitos ZnO-SiO_x obtenidos por la técnica Cat-CVD. Superf. vacío [online]. 2011, vol.24, n.3, pp.76-80. ISSN 1665-3521.

Zinc oxide- non-stoichiometric silicon dioxide (ZnO-SiO_x) composites were obtained by catalytic chemical vapor deposition (Cat-CVD) technique at 950 ⁰C. The experiments were carried out in the range of 800-1100 ⁰C. From X-ray diffraction (XRD) and Fourier transformed infrared spectroscopy (FTIR) analyses, we found that pure ZnO phase is obtained at 800 ⁰C. It was observed that increasing deposit temperature, the structure of deposited material is beginning to be dominated by SiO_x until to 1100 ⁰C, single amorphous SiO_x phase is obtained. However, it was found an intermediate temperature (950 ⁰C) to obtain ZnO-SiO_x composite. The gradually phase shift was attributed to both zinc (Zn) re-evaporation, and increased surface mobility of silicon (Si) atoms. Photoluminescence (PL) spectra showed two emission bands: one from 450 until 700 nm, and the other, a broad band from 600 to 1100 nm approximately. These emissions are generally related with oxygen vacancies (V_o) in ZnO and Si nanocrystals in SiO_x.

Palavras-chave : Ccomposite; ZnO-SiO_x; Cat-CVD; Photoluminescence; XRD.

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