Excitation intensity- and temperature-dependent photoluminescence in layered structured Tl2GaInSe2S2 crystals

Photoluminescence spectra of Tl2GaInSe2S2 layered crystals have been registered in the temperature range of 17-62 K and in the wavelength region of 525-690 nm. A broad visible photoluminescence band centered at 590 nm (2.10 eV) was observed at T 17 K. Variation of emission band has been studied as a function of laser excitation intensity in the 0.1-55.7 mW cm(-2) range. The analysis of the spectra reveals that the peak energy position changes with excitation intensity (blue shift). The radiative transitions from moderately deep donor level to shallow acceptor level were suggested to be responsible for the observed band. From X-ray powder diffraction study, the parameters of monoclinic unit cell of Tl2GaInSe2S2 were determined. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4792499]


Optical absorption and reflection studies of Tl4InGa3S8 layered single crystals
Goksen, K.; Hasanlı, Nızamı; Ozkan, H. (Institute of Physics, Polish Academy of Sciences, 2007-07-01)
The optical properties of Tl4InGa3S8 layered single crystals have been studied by means of transmission and reflection measurements in the wavelength region between 400 and 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 2.40 and 2.61 eV, respectively. Transmission measurements carried out in the temperature range of 10-300 K revealed the rate of change of the indirect band gap with temperature as g...
Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station
Aguilar, M.; et. al. (American Physical Society (APS), 2016-08-26)
A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 x 10(5) antiproton events and 2.42 x 10(9) proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range similar to 60 to similar to 500 GV, the antiproton (p) over bar, proton p, and positron e(+) fluxes are found to have nearly identical ri...
Optical properties of TlGa(SxSe1-x) 2 layered mixed crystals (0=x=1): Absorption edge and photoluminescence study at T=10 K
Hasanlı, Nızamı (Springer Science and Business Media LLC, 2018-09-01)
Transmittance measurements of layered mixed crystals were performed in the 1.80-2.80 eV photon energy range at . Band-gap energies of the studied crystals were estimated by means of the derivative spectra of transmittance and photon energy dependence of absorption coefficient. The compositional dependence of direct band-gap energy at revealed that as sulphur (selenium) composition is increased (decreased) in the mixed crystals, the direct band-gap energy increases from 2.19 eV () to 2.67 eV (). Photolumines...
Specific heat of NH4Br and NH4BrxCl1-x crystals close to the antiferroelectric transition
Yurtseven, Hasan Hamit (AIP Publishing, 2005-11-01)
We calculate the specific heat C-VI of NH4Br and mixed crystals of NH4BrxCl1-x using the Ising model for the transition between the disordered (D) and antiferro- (AF) electric phases in these crystalline systems. Our C-VI values, which we calculated for x(Br)=1, 0.26, and 0.51 are in good agreement, both below and above T-C, with the observed C-P data from the literature. Our value of congruent to 0.1 (T < T-C and T>T-C) for the critical exponent of the specific heat agrees with the value of 0.125 predicted...
Tuning Optical Absorption Edge by Composition and Temperature in TlGaS2xSe2((1-x)) Layered Mixed Crystals (0 <= x <= 1)
Hasanlı, Nızamı (Institute of Physics, Polish Academy of Sciences, 2012-10-01)
Optical properties of TlGaS2xSe2((1-x)) mixed crystals (0 <= x <= 1) have been studied using the transmission and reflection measurements in the wavelength range of 400-1100 nm. The optical indirect band gap energies were determined through the analysis of the absorption data. It was found that the energy band gaps increase with increase of sulfur atoms content in TlGaS2xSe2(1-x) mixed crystals. From the transmission measurements carried out in the temperature range of 10-300 K, the rates of change of the i...
Citation Formats
N. Hasanlı, “Excitation intensity- and temperature-dependent photoluminescence in layered structured Tl2GaInSe2S2 crystals,” JOURNAL OF APPLIED PHYSICS, pp. 0–0, 2013, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/43892.