Characterization and sensing properties of ZnO film prepared by single source chemical vapor deposition

Abstract

A novel deposition technique has been used to grow ZnO films. Good quality films were obtained on glass substrates by single source chemical vapor deposition (SSCVD), for gas sensing applications. The properties of ZnO films were investigated at different deposition temperatures 300, 350 and 400°C. X-ray diffraction results show that all deposited films were polycrystalline. The morphological, structural, optical and electrical properties of the films have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), cathodoluminescence (CL) and Hall effect techniques. The morphology of the deposited films evolves from columnar grains, to parallel plates as the substrate temperature increases. A significant increase in the relative intensities of the green and red emission with increasing deposition temperature has been observed. Electrical properties, relevant for gas sensing behavior have been investigated as well. In the particular case of CO an operating temperature of 300°C seems to yield the best sensitivity.