ZnO films with different preferred orientation or texturing were deposited via sol-gel method using different chelating agents. Thermolysis assisted chemical solution method was used to grow ZnO nanorods on ZnO films. The ZnO films with different preferred orientation and nanorods grown on those films were examined by characterization of gas sensing properties conducted at 300 oC using ethanol. Randomly grown ZnO films showed higher sensitivity comparing with oriented ZnO films due to larger specific surface area. When ZnO nanorods were grown on ZnO films with different orientation, no significant gas sensing response between two structures was observed. However, structural change from films to nanorods results in significant improvement in gas sensing properties. Therefore, the growth toward 3-dimensional nanostructure can play more important role in enhancing sensitivity than control of 2-dimensional film orientation.

Keywords: ZnO, Nanostructure, Sol-gel, Crystallographic orientation, Gas sensing.