STRUCTURAL AND RAMAN SCATTERING STUDIES OF ZnO Cu NANOCRYSTALS GROWN BY SPRAY PYROLYSIS

 

B. El Filali, T. V. Torchynska, A.I. Díaz Cano, M. Morales Rodriguez

 

 

The paper presents a simple method to produce the ZnO nanocrystals (NCs) doped with Cu atoms by means of the spray pyrolysis using Zinc acetylacetonate hydrate, copper acetylacetonate and chloroform as solvent. ZnO nanocrystals with 5–20 wt % Cu were deposited on the glass substrates at 400°C using the spray pyrolysis technique and then thermal annealed at 500°C for 2 hours in ambient atmosphere. The crystallinity and morphology of the films were characterized by SEM, XRD and Raman scattering methods. The XRD study indicates that ZnO films have a hexagonal wurtzite structure and the Cu addition enhances the preferential orientation along the (1 0 0). The Raman scattering spectrum of Cu doped ZnO nanocrystals thermal annealed at 500°C for 2 hours in ambient atmosphere demonstrates a set of Raman peaks related to the vibrational modes in ZnO for small Cu concentration (5-10%). In ZnO nanocrystals with higher Cu concentrations (15-20%) the CuO phase was detected by the XRD and Raman scattering methods. It was shown that the quality of ZnO NC films can be improved by copper doping with concentration less than 10%.