Studies on Characterization of Nanocrystalline Silver Sulphide Thin FilmsDeposited by Chemical Bath Deposition (CBD) and Successive Ionic LayerAdsorption and Reaction (SILAR) method

摘要

Nanocrystalline Silver Sulphide thin films were deposited at room temperature on glass substrate by two techniques: Chemical Bath Deposition (CBD) and Successive Ionic Layer Adsorption and Reaction (SILAR) technique. Silver nitrate and thiourea were used as basic precursors in both cases. The films were characterized by X-ray diffraction, scanning electron microscope and optical absorption measurements. X-ray diffraction patterns showed that both the films, as prepared, are of monoclinic (acanthite) structure with composition Ag2S. The average crystallite size of the films prepared by CBD and SILAR technique is found to be 25.61 nm and 21.38 nm, respectively. The optical properties were studied by measuring the absorption spectra. The band gap is 1.78 eV and 2.09 eV for the nanocrystalline Ag2S thin films prepared by CBD and SILAR technique respectively. It is observed from scanning electron microscopy (SEM) that the substrates are well-covered with the deposited Ag2S layers without cracks and pinholes