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The work investigated in this paper focused on the fabrication of WO3 films by the spray pyrolysis technique, and different analyses were made to find optimized samples for studying properties suitable for the application of gas sensing. The substrate temperature is the most important parameter among other spray parameters for the synthesis of thin films hence WO3 thin films were deposited on glass substrates by maintaining the substrate temperature at 350 ºC, 450 ºC, 550 ºC, and 650 °C using compressed air as a carrier gas. The influence of the substrate temperature on the structural, morphological, compositional, and optical properties of the WO3 thin films has been justified using XRD data. Good and enhanced crystallinity is observed for the film deposited at a substrate temperature of 550 ºC. The nonconventional properties were studied by different investigations and confirmed by past research work. The manipulation of surface morphology with the different deposition temperatures is monitored. Only the characteristic peaks of W and O are present in the fabricated WO3 thin films. The optical activity of about 70 to 80 % of the selected sample in the visible region (300 to 1200 nm) is found. The selective absorption activity of light in the ultraviolet region and visible region is checked. The obtained IR bands confirmed the inter bridge stretching and bending modes of W-O and O-W-O. A high response towards ammonia compared to other test gases is exhibited. The repeatability of WO3 towards NH3 over three periodic sensing cycles, response, and recovery time has also been discussed. From all the characteristic studies, it has been suggested that the fabricated WO3 thin films have been used in the health care field to detect the toxic NH3 gas

A noval study on the fabrication of virgin and nickel (Ni) doped stannic oxide (SnO2) thin films with different doping extent have been conducted to augment the properties of stannic oxide thin films to incorporate into the electric cell which utilizes sun’s energy. The influence of the Ni doping with various extents on the structural, optical and magnetic properties of the different synthesized samples of stannic oxide thin films are investigated byX-ray diffraction (XRD), Scanning electron microscopy (SEM), UV-Visible spectrophotometer and Vibrating Sample Magnetometer (VSM). All the fabricated samples of SnO2: Ni(1at%, 2at%, 3at% and 4at%) exhibited tetragonal structure of stannic oxide. The fusion of Ni into the stannic oxide lattice makes imperfection in the crystal and the presence of additional peaks confirms that the nickel domination is well observed. Increase in the extent of Ni doping causes diminution in optical band gap. The magnetic study reveals that the ferromagnetic signal is gradually enhanced with augment in doping concentration.

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