The structural and optical constants of Ag2S semiconductor nanostructure in the Far-Infrared

Reza Zamiri; Hossein Abbastabar Ahangar; Azmi Zakaria; Golnoosh Zamiri; Mehdi Shabani; Budhendra Singh; J M F Ferreira

doi:10.1186/s13065-015-0099-y

The structural and optical constants of Ag2S semiconductor nanostructure in the Far-Infrared

Chem Cent J. 2015 May 22:9:28. doi: 10.1186/s13065-015-0099-y. eCollection 2015.

Authors

Reza Zamiri¹, Hossein Abbastabar Ahangar², Azmi Zakaria³, Golnoosh Zamiri³, Mehdi Shabani⁴, Budhendra Singh⁵, J M F Ferreira⁴

Affiliations

¹ Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor 43400 UPM Malaysia ; Department of Materials and Ceramic Engineering (DEMaC), University of Aveiro, Campus Santiago, Aveiro, 3810-193 Portugal.
² Department of Chemistry, Faculty of Science, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan Iran.
³ Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor 43400 UPM Malaysia.
⁴ Department of Materials and Ceramic Engineering (DEMaC), University of Aveiro, Campus Santiago, Aveiro, 3810-193 Portugal.
⁵ TEMA-NRD, Mechanical Engineering Department and Aveiro Institute of Nanotechnology (AIN), University of Aveiro, Aveiro, 3810-193 Portugal.

Abstract

Background: In this paper a template-free precipitation method was used as an easy and low cost way to synthesize Ag2S 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 Ag2S was synthesized by a wet chemical precipitation method. Ag2S 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 Ag2S nanoparticles is around 0.96 eV, which is in good agreement with previous reports for the band gap energy of Ag2S nanoparticles (0.9-1.1 eV).

Conclusion: The crystallite size of the synthesized particles was obtained by Hall-Williamson plot for the synthesized Ag2S nanoparticles and it was found to be 217 nm. The Far-infrared optical constants of the prepared Ag2S semiconductor nanoparticles were evaluated by means of FTIR transmittance spectra data and K-K method. Graphical abstractThe Far-infrared optical constants of Ag2S semiconductor nanoparticles.

Keywords: Crystal structure; Infrared spectroscopy; Nanostructures; Optical properties; Raman spectroscopy; Semiconductors.