Absorption edge and optical constants of layered structured Tl2Ga2Se3S single crystals

The optical properties of Tl2Ga2Se3S layered crystals have been studied through transmission and reflection measurements in the photon energy range 1.13-2.82 eV. The optical indirect and direct transitions with band gap energies of 2.15 and 2.54 eV, respectively, were determined from the analysis of absorption data at room temperature. The dispersion of refractive index is discussed in terms of the Wemple-DiDomenico single-effective oscillator model. The refractive index dispersion parameters, namely oscillator and dispersion energies, oscillator strength and zero-frequency refractive index, were found to be 4.90 eV, 32.44 eV, 1.03x10(14) m(-2) and 2.76, respectively. Furthermore, the transmission measurements were made in the temperature range 10-300 K. As a result, the rate of indirect band gap variation with temperature gamma = -4.6x10(-4) eVK(-1) and the absolute zero value of the band gap energy E-gi(0) = 2.24 eV were obtained.


Dispersive optical constants of Tl2InGaSe4 single crystals
Qasrawi, A. F.; Hasanlı, Nızamı (IOP Publishing, 2007-09-01)
The structural and optical properties of Bridgman method grown Tl2InGaSe4 crystals have been investigated by means of room temperature x-ray diffraction, and transmittance and reflectance spectral analysis, respectively. The x-ray diffraction technique has shown that Tl2InGaSe4 is a single phase crystal of a monoclinic unit cell that exhibits the lattice parameters of a = 0.77244 nm, b = 0.64945 nm, c = 0.92205 nm and beta = 95.03 degrees . The optical data have revealed an indirect allowed transition band ...
Optoelectronic properties of Ga(4)Se(3)S-layered single crystals
QASRAWI, ATEF FAYEZ HASAN; Hasanlı, Nızamı; Ilaiwi, K. F. (IOP Publishing, 2008-07-01)
The optoelectronic properties of Bridgman method-grown Ga(4)Se(3)S single crystals have been investigated by means of room temperature electrical resistivity, temperature-dependent photosensitivity and temperature-dependent optical absorption. The photosensitivity was observed to increase with decreasing temperature, the illumination dependence of which was found to exhibit monomolecular recombination in the bulk at 300 K. The absorption coefficient, which was calculated in the incident photon energy range ...
Radiative damping of whistlers in a dense magnetoactive plasma waveguide
Yilmaz, A; Oke, G; Rukhadze, A; Bilikmen, S (IOP Publishing, 1996-06-01)
The absorption of whistler waves in a magnetized cylindrical plasma due to coupling with oblique Langmuir waves is investigated. Two types of mechanisms exist for whistler absorption. The first one is related to the excitation of Langmuir waves in the volume of the dense plasma and their subsequent absorption due to the electron collisions. The second one is the emission of Langmuir waves outside of the cylindrical plasma when it is surrounded by the rare plasma. The relation between these whistler absorpti...
Optical constants of silver and copper indium ternary sulfides from infrared reflectivity measurements
Hasanlı, Nızamı (Elsevier BV, 2016-03-01)
Infrared reflection spectra are obtained in the frequency range of 50-2000 cm(-1) for AgIn5S8 and CuIn5S8 single crystals grown by Bridgman method. All four infrared-active modes are detected, which are in full agreement with the prediction of group-theoretical analysis. Spectral dependence of optical parameters; real and imaginary parts of the dielectric function, the function of energy losses, refractive index, absorption index and absorption coefficient were calculated from reflectivity experiments. The ...
Dispersive optical constants and temperature tuned band gap energy of Tl2InGaS4 layered crystals
Goksen, K.; Hasanlı, Nızamı; Ozkan, H. (IOP Publishing, 2007-06-27)
The optical properties of Tl2InGaS4 layered single crystals have been studied by means of transmission and reflection measurements in the wavelength range of 400-1100 nm. The analysis of the room temperature absorption data revealed the presence of both optical indirect and direct transitions with band gap energies of 2.35 and 2.54 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 =...
Citation Formats
N. Hasanlı, “Absorption edge and optical constants of layered structured Tl2Ga2Se3S single crystals,” PHYSICA SCRIPTA, pp. 0–0, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46564.