Synthesis of ZnO Particles by Electrolysis
ZnO with a good crystallinity and visible photoluminescence at room temperature around 518 nm and 605 nm obtained by an electrolytic method using urea and zinc nitrate is presented. An electrolytic Teflon cell was used for the process using tungsten wire and aluminum foil as electrodes, the tungsten wire was introduced in a solution of water, zinc nitrate and urea. The electrical potential was modified, keeping constant the growth time. As substrate and cathode a 1-3 -cm, (100), n type, silicon wafer was used. The crystalline structure and photoluminescence showed interesting changes when the electrical potential was modified. XRD (X Ray Diffraction) performed on the films showed characteristic diffraction peaks of ZnO obtained in other works. The amplitude of these peaks changed with the electrical potential applied, with a predominance of the (100), (002) and (101) planes. The photoluminescence (PL) bands changed with the electrical conditions too. At low electrical currents a predominance of the green band (520 nm) was observed, and another band around 600 nm appeared from high current conditions, this behavior can be associated with different defects generated during the grow process. From these results we conclude that the change in the electrical current produces changes in the structural and optical characteristics of the material.
Luís Guerra ROSA and Fernanda MARGARIDO
G. García-Salgado et al., "Synthesis of ZnO Particles by Electrolysis", Materials Science Forum, Vols. 636-637, pp. 418-422, 2010