Metal organic chemical vapor deposition and investigation of structural, optical and gas sensing characteristics of ZnO thin film grown on quartz

Nano-crystalline materials having large surface to volume ratio are promising candidates for gas sensor application. In order to achieve this nano crystallinity ZnO thin film is deposited on the quartz substrate by Metal Organic Chemical Vapor Deposition (MOCVD) technique. Diethyl-zinc (DEZn) and tert-butanol (TBOH) are used as the zinc and oxygen precursors respectively. The film properties are analyzed by XRD, FESEM and UV-visible spectroscopy. X-ray diffraction (XRD) studies showed that the film is textured along (002) plane. The FESEM images reveal the nano-size of the particles. From the optical studies it is found that the film is transparent in nature and the band gap is 3.24 eV. The gas sensing characteristics of the grown film is investigated in presence of CO gas as a function of temperature and gas concentration. The sensing results show that MOCVD grown ZnO thin films can be used as attractive reducing gas sensors.