Author(s): Monteiro, R. C. C. ; Kullberg, A. T. ; Lopes, A. A. S. ; Pinto, J. V. ; Nunes, D. ; Gonçalves, A. ; Fortunato, E. ; Castro, F.
Date: 2015
Persistent ID: https://hdl.handle.net/1822/37346
Origin: RepositóriUM - Universidade do Minho
Subject(s): Sputtering; ZnO waste; Zincite; Ceramic target; Sintering; Thin film; Optical properties
The feasibility of using a zinc oxide rich waste (ZnO>95%), dust originated in the brass smelting industrial process, as a raw material to produce targets to be used in radiofrequency magnetron sputtering (RFMS) deposition of ZnO thin films was investigated. The ZnO waste was characterized in terms of chemical and mineralogical compositions and particle size distribution. The targets were prepared by uniaxial pressing of the ZnO waste followed by sintering in air at a temperature in the range 900-1200 ºC. The density of sintered targets increased with sintering temperature, and zincite (ZnO) was the predominant crystalline phase identified by X-ray diffraction (XRD). Scanning electron microscopy (SEM) revealed zincite grains, with an average size ~2 m and a nonhomogeneous microstructure due to the presence of dense aggregates. Preliminary MS thin film deposition tests on a glass substrate produced transparent nanostructured ZnO thin films with a homogeneous microstructure. Research work is underway to process ZnO waste-based targets with an improved microstructure in order to obtain RFMS deposited ZnO thin films with optimized final electrical and optical properties.
