Vanadium-doped zinc oxide films for piezoelectric application

Nanocrystalline zinc oxide:vanadium (ZnO:V) films were deposited over thoroughly cleaned glass substrates using the reactive direct current magnetron sputtering technique. The deposited ZnO:V films were analyzed for their structural, morphological, optical and electrical properties using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), UV-visible spectrophotometry and the two-probe method, respectively. Microstructural parameters of the films varied with respect to substrate temperature, substrate bias and sputtering powers. FE-SEM micrographs of the films showed that the prepared films were porous when compared with pure ZnO films. ZnO:V films were highly transparent and the optical band gap value of the films varied between 3·1 and 3·37 eV. Piezoelectric generation of the ZnO:V films was tested by different testing methodologies. The lab-scale device fabricated in the present work generated 100 µV upon applying vibration. Scaling up this device would yield piezoelectricity of higher orders of voltages.