- ZnO is synthesized by microwave assisted technique. The XRD, TEM, SAED and SEM characterization of sample is carried out for studying crystal structure, particle size, crystalline nature and surface morphology of ZnO samples. The thick films of ZnO sample were fabricated by screen printing technique and its I-V characteristics and electrical conductivity were studied. The gas sensing response of ZnO thick film sensor towards 450 ppm of H2S, LPG, NH3 and CO2 gas was investigated. The thick film showed response 15 towards H2S at 150 0C, response 3 to NH3, response 2 for LPG and no response to CO2. The variation of response with H2S concentration was also studied. The response time and recovery time of sensor was 70 second. It was selective to H2S in presence of LPG, NH3 and CO2 gases. The thick film showed good reproducibility and stability for H2S.

Cu doped ZnO film (Zn0.95Cu0.05O) was fabricated by simple and cost-effective screen printing method. The structural and optical properties of prepared film was studied through X-ray diffraction (XRD) and UV-Vis spectroscopy techniques respectively. XRD analysis revealed the polycrystalline nature of prepared film with hexagonal structure. The optical band gap determined from UV-Vis analysis was found to be 3.40 eV. The gas sensing performance of prepared film was studied at room temperature toward different concentrations of NO2 ranging in between 1ppm – 5ppm. The response and recovery time was noted as 13s and 92s respectively. All these outcomes shows that the Cu doped ZnO film shows enhanced gas sensing performance and can be utilized for industrial scale production of gas sensors.

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Lithium ion conducting polymer electrolyte films based on polyvinyl alcohol (PVA) with different concentration of lithium perchlorate salt, using a solution cast technique, have been prepared. The Solid polymer electrolyte (SPE) hasbeen characterized by XRD technique. The XRD analysis reveals the amorphous nature of the polymer electrolyte. Polymer sample of PVA with different concentration of lithium salt (0, 5, 10, 20) wt% with double distilled water as solvent have been prepared and studied. High conductivity of 1.85771X10-07 has been observed for the PVA with 20% LiClO4. The temperature dependent conductivity of polymer electrolyte follows the Arrhenius relationship which shows hopping of ion in the polymer system. The experiment result showed that the D.C electrical conductivity increased with increasing the lithium salt concentration.

In this study, theSolid polymer electrolyte (SPE)containing polyvinyl alcohol (PVA) and lithium perchloride(LiClO4) have been prepared by using solution cast technique.The objective of this study is to investigate the influence of LiClO4 inorganic salt on the AC conductivity of the electrolyte. For that purpose, the PVA sample with LiClO4 inorganic salt was prepared with different concentration (0, 5, 10, 15 and 20)wt.% of LiClO4 salt and different thickness. XRD analysis of the sample reveals that PVA shows broad peak at 26=19.84° and degree of crystallinity decrease by adding the concentration of lithium salt.The electrical conductivity of the material is measured using LCR meter.The experimental results shows that the AC electrical conductivity increases with increasing the temperature and concentration of Li salt.The dielectric constant values of SPE decreases with increase in frequency and increases with increase in temperature. Maximum conductivity of PVA with 20% LiClO4 at 353K and frequency 500kHz is found to be 3.51*10-2 s/cm.