Temperature dependent band gap in SnS2xSe(2-2x) (x=0.5) thin films


Delice S., Isik M., Gullu H. H. , Terlemezoglu M., Surucu O. B. , Gasanly N., ...More

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING, vol.114, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 114
  • Publication Date: 2020
  • Doi Number: 10.1016/j.mssp.2020.105083
  • Journal Name: MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Applied Science & Technology Source, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, INSPEC, Metadex
  • Keywords: SnS2, SnSe2, Thin films, Optical properties, SNSE, NANOSHEETS, SE
  • Middle East Technical University Affiliated: Yes

Abstract

Structural and optical properties of SnS2xSe(2-2x) thin films grown by magnetron sputtering method were investigated for composition of x = 0.5 (SnSSe) in the present study. X-ray diffraction, energy dispersive X-ray spectroscopy, atomic force microscopy and scanning electron microscopy methods were used for structural characterization while temperature-dependent transmission measurements carried out at various temperatures in between 10 and 300 K were accomplished for optical investigations. X-ray diffraction pattern of studied composition presented peaks at positions which are between those of SnSe2 and SnS2. Transmittance spectra recorded at all applied temperatures were analyzed using well-known Tauc relation. Analyses revealed the direct band gap energy value of SnSSe thin films as 1.75 eV at room temperature. Change of band gap energy as a response to varying temperature were discussed in the study by utilizing Varshni relation. It was shown that variation of gap energy values was well-matched with the Varshni's empirical formula. Energy band gap at absolute zero and rate of change of band gap with temperature were found to be 1.783 eV and -2.1 x 10(-4) eV K-1, respectively.