Band gap and refractive index tunability in thallium based layered mixed crystals

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HASANLI N.

JOURNAL OF APPLIED PHYSICS, cilt.118, sa.3, 2015 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 118 Sayı: 3
  • Basım Tarihi: 2015
  • Doi Numarası: 10.1063/1.4926864
  • Dergi Adı: JOURNAL OF APPLIED PHYSICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Compositional variation of the band gap energy and refractive index of TlMeX2-type (Me = Ga or In and X = S or Se) layered mixed crystals have been studied by the transmission and reflection measurements in the wavelength range of 400-1100 nm. The analysis of absorption data of TlGa1-xInxSe2, TlGa(S1-xSex)(2), TlGa1-xInxS2, and TlIn(Se1-xSx)(2) mixed crystals revealed the presence of both optical indirect and direct transitions. It was found that the energy band gaps of mixed crystals decrease at the replacing of gallium atoms by indium and of sulfur atoms by selenium ones. Through the similar replacing of atoms (smaller atoms by larger ones) in the studied mixed crystals, the refractive index shows the quite opposite behavior. (C) 2015 AIP Publishing LLC.