A low temperature synthesis of Ag2S nanostructures and their structural, morphological, optical, dielectric and electrical studies: An effect of SDS surfactant concentration

Nanostructures of Silver sulfide (Ag2S) possess wide range of applications as infrared detectors, resistance-switches and nonvolatile memory devices. Hence, the authors aim is to synthesize the Ag2S nanostructures using facile chemical route at low temperature (i.e. similar to 65 degrees) with different concentrations (i.e. from 0 to 1 g) of sodium dodecyl sulfate (SDS) surfactants for such applications. High crystallinity and single phase was proved by X-ray diffraction and EDX analyses as there was no peak due to impurity was seen. The crystallite size was estimated and found in range of 39-44 nm. SEM analysis showed the homogeneous nanoparticles formation is all samples and the size was obtained in range of 40-60 nm for Ag2S samples prepared with 0, 0.1, 0.25 g SDS, however at higher SDS concentrations the size was found in range of 30-50 nm. Diffused reflectance spectra were measured for all samples and Kubelka-Munk theory is applied to estimate the energy gap which is found in range of 1-1.04 eV. The refractive index was also estimated in the range of 1.7-2 in 200-1200 nm wavelength region. The prepared nanoparticles possess high dielectric constant and electrical conductivity.