CoO doping effects on the ZnO films through EBPDV technique

¹ Instituto de Física de São Carlos, Universidade de São Paulo, PO Box 369, 13560-970 São Carlos, SP, Brazil
² Instituto de Física – Universidade Federal de Goiás, Campus II, PO Box 131, 74001-970 Goiânia, GO, Brazil
³ Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, 12231-280 São José dos Campos, SP, Brazil
⁴ Instituto de Geociências e Ciências Exatas – Universidade Estadual Paulista, 13506-900 Rio Claro, SP, Brazil
⁵ Departamento de Engenharia de Materiais – Universidade Federal de Campina Grande, 58109-970 Campina Grande, PB, Brazil

^a e-mail: m.basso@if.sc.usp.br

Received: 7 May 2013
Revised: 29 January 2014
Accepted: 3 February 2014
Published online: 3 March 2014

Abstract

Nanometric Zn_1–xCo _xO (x = 0.020, 0.025 and 0.030 in mol.%) nanopowders were obtained from low temperature calcination of a resin prepared using the Pechini’s method. Firing the Zn_1–xCo_xO resin at 400 °C/2 h a powder with hexagonal structure was obtained as measured by X-ray diffraction (XRD). The powder presented average particle size of 40 nm observed by field emission scanning electronic microscopy (FE-SEM) micrographs and average crystallite size of 10 nm calculated from the XRD using Scherrer’s equation. Nanocrystalline Zn_1–xCo _xO films with good homogeneity and optical quality were obtained with 280–980 nm thicknesses by electron beam physical vapour deposition (EBPVD) under vacuum onto silica substrate at 25 °C. Scanning electron microscopy with field emission gun showed that the film microstructure is composed by spherical grains and some needles. In these conditions of deposition the films presented only hexagonal phase observed by XRD. The UV-visible-NIR and diffuse reflectance properties of the films were measured and the electric properties were calculated using the reflectance and transmittance spectra.