Study of the optical and photoelectrical properties of TlGaSeS layered single crystals

Delice, S.
Hasanlı, Nızamı
Transmission spectra (7) of TIGaSeS crystals in the photon energy (hv) range 1.38-2.38 eV are used to determine the energy gap. The indirect band gap of 2.30 eV was established employing the photon energy dependence of the first derivative dT/d(hv) and the photon energy dependence of absorption coefficient. In order to obtain information about the defect states in the energy gap of TlGaSeS crystals, photoconductivity (PC) measurements are performed in the 140-300 K range. Photoconductivity spectra in the photon energy range of 1.77-3.10 eV show two peaks related to intrinsic and extrinsic excitations. It was revealed that the first peak shifts slightly towards the low energy side with increasing temperature, whereas the second one shifts more significantly to the high energy range. It was assumed that for latter peak the deviating PC originates from the distributed energy levels in the band gap where the photoelectrons arise or where they go.


Visible photoluminescence from chain Tl4In3GaSe8 semiconductor
Hasanlı, Nızamı (IOP Publishing, 2006-07-05)
The emission band spectra of undoped Tl4In3GaSe8 chain crystals have been studied in the 16-300 K temperature range and the 535-740 nm wavelength range. Two visible photoluminescence bands centred at 589 and 633 nm were observed at T = 16 K. Variations of both bands have been investigated over a wide range of laser excitation intensity ( 3 x 10(-4) -1.2 W cm(-2)). Radiative transitions with energies of 2.10 and 1.96 eV from two upper conduction bands to two shallow acceptor levels (0.03 and 0.01 eV), respec...
Observation of in situ enhanced crystallization, negative resistance effect and photosensitivity in Tl2InGaSe4 crystals
Qasrawi, A. F.; Irshaid, Tahani M. A.; Hasanlı, Nızamı (Elsevier BV, 2021-02-01)
In this work, we report the properties of Tl2InGaSe4 crystals as multifunctional material. Namely, Tl2InGaSe4 crystals are grown by the modified Bridgman method using mixtures of TlInSe2 (50%) and TlGaSe2 (50%) single crystals. The enhanced crystallization and structural stabilities are monitored by the X-ray diffraction technique during the in situ heating and cooling cycles. The structural analyses on the Tl2InGaSe4 crystals revealed domination of both of the monoclinic and tetragonal phases in the crysta...
Synthesis of zirconium tungstate-zirconia core-shell composite particles
Khazeni, Nasser; MAVİŞ, BORA; Gündüz, Güngör; Colak, Uner (Elsevier BV, 2011-11-01)
In this work, ZrW(2)O(8)-ZrO(2) core-shell composite particles were synthesized. ZrW(2)O(8) that was used in the core is a material with negative coefficient of thermal expansion, and it was synthesized from a high-pH precursor based on use of tungstic acid and zirconium acetate. Shell layer was composed of ZrO(2) nanocrystallites and precipitated from an aqueous solution by urea hydrolysis. While volume of the shell was effectively controlled by the initial zirconium ion concentration in the solutions, the...
Transient and steady state photoelectronic analysis in TlInSe2 crystals
QASRAWI, ATEF FAYEZ HASAN; Hasanlı, Nızamı (Elsevier BV, 2011-08-01)
The temperature and illumination effects on the transient and steady state photoconductivities of TlInSe2 crystals have been studied. Namely, two recombination centres located at 234 and at 94 meV and one trap center located at 173 meV were determined from the temperature-dependent steady state and transient photoconductivities, respectively. The illumination dependence of photoconductivity indicated the domination of sublinear and supralinear recombination mechanisms above and below 160 K, respectively. Th...
Analysis of the Hall effect in TlGaTe2 single crystals
QASRAWI, ATEF FAYEZ HASAN; Hasanlı, Nızamı (IOP Publishing, 2009-06-10)
The electrical resistivity and Hall coefficient of p-type TlGaTe2 crystals were measured in the temperature range of 110-320 K. The electrical resistivity, charge carrier density and Hall mobility data for the crystals have been analyzed by means of existing theories and models to determine the extrinsic energy levels, the carrier effective mass, the donor and acceptor concentrations and the dominant scattering mechanism in the crystal as well. The analysis of the temperature-dependent electrical resistivit...
Citation Formats
S. Delice and N. Hasanlı, “Study of the optical and photoelectrical properties of TlGaSeS layered single crystals,” MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING, pp. 72–75, 2017, Accessed: 00, 2020. [Online]. Available: