Temperature-tuned band gap energy and oscillator parameters of Tl2InGaSe4 semiconducting layered single crystals

HASANLI N.

CRYSTAL RESEARCH AND TECHNOLOGY, cilt.44, sa.3, ss.322-326, 2009 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 44 Sayı: 3
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1002/crat.200800369
  • Dergi Adı: CRYSTAL RESEARCH AND TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.322-326
  • Anahtar Kelimeler: optical constants, dispersion of refractive index, optical band gap, layered crystals, ELECTRICAL-PROPERTIES, TLGASE2, ABSORPTION, SPECTRA, TLINS2
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

The optical properties of Tl2InGaSe4 layered single crystals have been studied through the transmission and reflection measurements in the wavelength range of 500-1100 nm. The analysis of room temperature absorption data revealed the presence of both optical indirect and direct transitions with band gap energies of 1.86 and 2.05 eV, respectively. Transmission measurements carried out in the temperature range of 10-300 K revealed that the rate of change of the indirect band gap with temperature is gamma = -4.4 x 10(-4) eV/K. The absolute zero value of the band gap energy was obtained as E-gi(0) = 1.95 eV. The dispersion of the refractive index is discussed in terms of the single oscillator model. The refractive index dispersion parameters: oscillator wavelength and strength were found to be 2.53 x 10(-7) m and 9.64 x 10(13) m(-2), respectively. (c) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim