SURFACE MORPHOLOGICAL, STRUCTURAL AND HYDROGEN SENSING CHARACTERIZATION OF PD DOPED ZnO THIN FILMS DEPOSITED BY SILAR

Both Zinc Oxide(ZnO) and Palladium (Pd) doped ZnO thin films prepared by Successive Ionic Layer Adsorption and Reaction technique called SILAR from Sodium Zincate complex. For the structural and morphological studies of the thin films X-ray diffraction(XRD) and Scanning Electron Microscopy (SEM) has done . Strong preferred c-axis orientation happen in both the undoped and Pd-doped ZnO thin films. SEM micrograph reveals that ZnO possess round shaped particles whereas Pd-doped ZnO shows off-sherical particles and compact grains. EDX done for investigating Pd incorporation in the film. Hydrogen (H2) sensing properties of Palladium(Pd) doped ZnO thin films has been studied. behaviors of the ZnO – based gas sensor For 10% Pd doped ZnO, the sensitivity and response time behaviors to hydrogen gas were investigated . Sensitivity dependence on the temperature was tested and the optimum operation temperature was at around 310 0C. The response time for the Pd doped ZnO film was 60 sec and the recovery time was 120 sec. The temperature variation of sensitivity was studied and the maximum sensitivity of 72% was observed at around 300 0C for 1.6 vol% H2 in air.