Optical properties of TlGaSeS layered single crystals

2007-12-01
The optical properties of TlGaSeS layered single crystals have been investigated by measuring the transmissions and the reflections in the wavelength region between 400 and 1100 nm. The optical indirect transitions with a band gap energy of 2.27 eV and direct transitions with a band gap energy of 2.58 eV were found by means of the analysis of the absorption data at the room temperature. The rate of change of the indirect band gap with temperature, that is, gamma = -3.2 x 10(-4) eV/K, was determined from the transmission measurements in the temperature range of 10 - 300 K. The absolute zero value of the band gap energy was obtained as E-gi(0) = 2.34 eV. The dispersion of the refractive index is discussed in terms of the Wemple-DiDomenico single-effective-oscillator model. The oscillator energy, the dispersion energy, the oscillator strength, and the zero-frequency refractive index, which are all refractive-index dispersion parameters, were found to be 4.71 eV, 28.98 eV, 8.88 x 10(13) m(-2) and 2.67, respectively. The parameters of the monoclinic unit cell were found by studying the X-ray powder diffraction.
JOURNAL OF THE KOREAN PHYSICAL SOCIETY

Suggestions

Optical properties of Tl2In2Se3S layered single crystals
Güler, Işıkhan; Hasanlı, Nızamı (2010-01-01)
The optical properties of Tl2In2Se3S layered single crystals have been analyzed using transmission and reflection measurements in the wavelength region between 500 and 1100 nm. The optical indirect transitions with a band gap energy of 1.96 eV and direct transitions with a band gap energy of 2.16 eV were determined from analysis of absorption data at room temperature. Dispersion of the refractive index is discussed in terms of the Wemple-DiDomenico single-effective-oscillator model. The refractive index dis...
Specific features of the optical spectra in Tl2In2S3Se layered single crystals
Hasanlı, Nızamı; Güler, Işıkhan (2007-06-01)
The optical properties of Tl2In2S3Se layered single crystals have been studied by means of transmission and reflection measurements in the wavelength range of 450-1100 nm. The analysis of the absorption data revealed the presence of both optical indirect and direct transitions with energy band gaps of 2.16 and 2.42 eV, respectively. The observed coexistence of indirect and direct energy band gaps is related to the anisotropy of the TI-containing layered crystals. The dispersion of the refractive index is di...
Temperature-tuned band gap energy and oscillator parameters of TlInSeS layered single crystals
Hasanlı, Nızamı; Güler, Işıkhan (2008-09-10)
The parameters of monoclinic unit cell of TlInSeS layered crystals were determined from X-ray powder diffraction study. The optical properties of TlInSeS have been investigated by means of transmission and reflection measurements in the wavelength range of 500-1100 nm. The optical indirect transitions with band gap energy of 2.05 eV and direct transitions with band gap energy of 2.21 eV were found by means of the analysis of the absorption data at room temperature. Transmission measurements carried out in t...
Absorption edge and optical constants of Tl2Ga2S3Se crystals from reflection and transmission, and ellipsometric measurements
Isik, M.; Hasanlı, Nızamı (2012-06-15)
The optical properties of Tl2Ga2S3Se layered crystalline semiconductors were investigated from transmission, reflection and ellipsometric measurements. The experimental results of the room temperature transmission and reflection measurements performed in the wavelength range of 400-1100 nm showed the presence of both indirect and direct transitions in the band structure of the crystals with 2.38 and 2.62 eV band gap energies.
Compositional dependence of refractive index and oscillator parameters in T1GaS(2x)Se(2(1-x)) layered mixed crystals (0 <= x <= 1)
Hasanlı, Nızamı (2012-09-14)
Optical characterization of TIGaS2xSe2(1-x) mixed crystals have been carried out at room temperature using the transmission and reflection measurements in the wavelength range of 400-1100 nm. The spectral dependence of the refractive index for all compositions of studied crystals were obtained. The dispersion of the refractive index is discussed in terms of the Wemple-DiDomenico single-effective-oscillator model. The compositional dependencies of refractive index dispersion parameters: oscillator energy, di...
Citation Formats
I. Güler and N. Hasanlı, “Optical properties of TlGaSeS layered single crystals,” JOURNAL OF THE KOREAN PHYSICAL SOCIETY, pp. 2031–2035, 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31850.