Low-temperature absorption edge and photoluminescence in layered structured Tl2Ga2S3Se single crystals

The absorption edge of undoped Tl2Ga2S3Se crystals have been studied through transmission and reflection measurements in the wavelength range 440-1100 nm and in the temperature range 10-300 K. The absorption edge was observed to shift toward lower energy values with increasing temperature. As a result, the rate of the indirect band gap variation with temperature gamma = -2.6 x 10(-4) eV/K and the absolute zero value of the band gap energy E-gi(0)=2.42 eV were obtained.


ALLAKHVERDIEV, KR; Hasanlı, Nızamı; AYDINLI, A (1995-06-01)
Low-temperature photoluminescence spectra of TlInS2, TlIn0.95 Ga0.05S2 and TlIn0.8Ga0.2S2 layer crystals were studied in the temperature range 14-220 K. The temperature dependencies of bands 2.374eV (A), 2.570 eV (E) and 2.576 eV (F) for TlInS2 are interpreted by supposing that the crystal undergoes structural phase transitions. Band A is considered to come from a donor-acceptor recombination channel.
Low-temperature photoluminescence in CuIn5S8 single crystals
Hasanlı, Nızamı (2016-06-01)
Photoluminescence (PL) spectra of CuIn5S8 single crystals grown by Bridgman method have been studied in the wavelength region of 720-1020 nm and in the temperature range of 10-34 K. A broad PL band centred at 861 nm (1.44 eV) was observed at T = 10 K. Variations of emission band has been studied as a function of excitation laser intensity in the 0.5- 60.2 mW cm(-2) range. Radiative transitions from shallow donor level located at 17 meV below the bottom of the conduction band to the acceptor level located at...
Low-temperature thermoluminescence in layered structured Ga0.75In0.25Se single crystals
Isik, M.; Bulur, Enver; Hasanlı, Nızamı (2012-12-25)
Defect centers in Ga0.75In0.25Se single crystals have been studied performing the thermoluminescence measurements in the temperature range of 10-300 K. The observed glow curves were analyzed using curve fitting, initial rise, and different heating rate methods to determine the activation energies of the defect centers. Thermal cleaning process has been applied to decompose the overlapped curves. Four defect centers with activation energies of 9, 45,54 and 60 meV have been found as a result of the analysis. ...
Low-temperature photoluminescence spectra of layered semiconductor TlGaS2
Hasanlı, Nızamı; Bek, Alpan; Yılmaz, İsmail Ömer (Elsevier BV, 1998-1)
Photoluminescence (PL) spectra of TlGa& layered single crystals were studied in the wavelength region 500-860 nm and in the temperature range 9.5-293 K. We observed a total of three PL bands centered at 568 nm (2.183 eV, A-band), 718 nm (1.727 eV, B-band) and 780 nm (1.590 eV, C-band) at various temperatures. We have also studied the variations of the A- and B-band intensities vs excitation laser density in the range from 7 X 10e2 to 9 W cm-‘. The A- and B-bands were found to be due to radiative transitions...
Low-temperature visible photoluminescence spectra of TlGaSe2 layered crystal
Hasanlı, Nızamı; Aydinli, A; Baten, SMA (2000-02-01)
The photoluminescence (PL) spectra of TlGaSe2 layered single crystals were investigated in the 8.5-35 K temperature, 0.2-15.2 W cm(-2) excitation laser intensity, and in the 600-700 nm wavelength range. The PL spectrum has a slightly asymmetric Gaussian lineshape with a peak position located at 1.937 eV (640 nm) at 8.5 K. The PL is quenched with increasing temperature. The blue shift of the PL peak and the sublinear increase of the PL intensity with increasing laser intensity is explained using the inhomoge...
Citation Formats
N. Hasanlı, “Low-temperature absorption edge and photoluminescence in layered structured Tl2Ga2S3Se single crystals,” PHYSICA B-CONDENSED MATTER, pp. 4318–4322, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32904.