Nanostructure of Cr-doped ZnO thin films by dip coating

Abstract

This study aims to examine the effect of calcination conditions on the microstructure of Cr-Doped ZnO Thin Films. Thermal decomposition was complete at lower than 400°C. Fourier Transform Infrared spectroscopy (FTIR) revealed a great increase in the peak intensity of the Cr-O functional group with increasing calcination temperature. The average crystallite sizes were in the range between 3 and 20 nm. Cr doping also resulted in dramatic crystallite size reduction. Field emission scanning electron microscopy (FESEM) revealed relatively porous structure with particle sizes matched with those calculated by Scherrer's equation. Thin, elongated plates were found to decorate throughout the film surface. Film roughness appeared to increase as examined by atomic force microscopy (AFM). The possible incorporation of Cr into ZnO was further confirmed by both lattice refinement and an increase in the band gap due to alteration in the conduction band structure.

Keywords:

• ZnO
• Dip coating
• Thin film
• Calcination

Acknowledgements

The film processing was performed by an undergraduate student (Fairus Pohmaereesor) at Silpakorn University. The author acknowledges the Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology at Silpakorn University for its financial support.