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Temperature‐tuned band gap energy and oscillator parameters of Tl 2 InGaSe 4 semiconducting layered single crystals
Author(s) -
Gasanly N. M.
Publication year - 2009
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.200800369
Subject(s) - refractive index , band gap , dispersion (optics) , oscillator strength , wavelength , materials science , range (aeronautics) , atmospheric temperature range , absorption (acoustics) , reflection (computer programming) , analytical chemistry (journal) , chemistry , optics , optoelectronics , spectral line , physics , chromatography , astronomy , meteorology , computer science , composite material , programming language
Abstract The optical properties of Tl 2 InGaSe 4 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 γ = – 4.4 × 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 × 10 –7 m and 9.64 × 10 13 m –2 , respectively. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)