Effect of temperature and isomorphic atom substitution on optical absorption edge of TlInS2xSe2(1-x) mixed crystals (0.25 <= x <= 1)


CRYSTAL RESEARCH AND TECHNOLOGY, vol.45, no.5, pp.525-528, 2010 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 45 Issue: 5
  • Publication Date: 2010
  • Doi Number: 10.1002/crat.200900653
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.525-528
  • Keywords: optical band gap, semiconductors, layered crystals, LATTICE-PARAMETERS, SINGLE-CRYSTALS, TLINS2, TLGASE2, SPECTRA
  • Middle East Technical University Affiliated: Yes


The optical properties of the TlInS2xSe2(1-x) mixed crystals (0.25 <= x <= 1) have been investigated through the transmission and reflection measurements in the wavelength range of 400-1100 nm. The optical indirect band gap energies were determined by means of the analysis of the absorption data. It was found that the energy band gaps decrease with the increase of selenium atoms content in the TlInS2xSe2(1-x) mixed crystals. The transmission measurements carried out in the temperature range of 10-300 K revealed that the rates of change of the indirect band gaps with temperature are gamma = -9.2x10(-4) eV/K, -6.1x10(-4) eV/K, -4.7x10(-4) eV/K and -5.6x10(-4) eV/K for TlInS2, TlInS1.5Se0.5, TlInSSe and TlInS0.5Se1.5 crystals, respectively. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim