The structural and optical constants of Ag(2)S semiconductor nanostructure in the Far-Infrared

BACKGROUND: In this paper a template-free precipitation method was used as an easy and low cost way to synthesize Ag(2)S semiconductor nanoparticles. The Kramers–Kronig method (K–K) and classical dispersion theory was applied to calculate the optical constants of the prepared samples, such as the reflective index n(ω) and dielectric constant ε(ω) in Far-infrared regime. RESULTS: Nanocrystalline Ag(2)S was synthesized by a wet chemical precipitation method. Ag(2)S nanoparticle was characterized by X-ray diffraction, Scanning Electron Microscopy, UV-visible, and FT-IR spectrometry. The refinement of the monoclinic β-Ag2S phase yielded a structure solution similar to the structure reported by Sadanaga and Sueno. The band gap of Ag(2)S nanoparticles is around 0.96 eV, which is in good agreement with previous reports for the band gap energy of Ag(2)S nanoparticles (0.9–1.1 eV). CONCLUSION: The crystallite size of the synthesized particles was obtained by Hall-Williamson plot for the synthesized Ag(2)S nanoparticles and it was found to be 217 nm. The Far-infrared optical constants of the prepared Ag(2)S semiconductor nanoparticles were evaluated by means of FTIR transmittance spectra data and K–K method. [Figure: see text]