Fizik Bilim Dalı
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/1819
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Browsing Fizik Bilim Dalı by Author "Gasanly, N."
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Article Citation - WoS: 5Citation - Scopus: 6Characteristic Features of Thermoluminescence in Neodymium-Doped Gallium Sulfide(Wiley, 2018) Isik, M.; Ahmedova, F.; Guseinov, A.; Gasanly, N.; Guler, I.; 101531; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya ÜniversitesiThe thermoluminescence (TL) of neodymium-doped gallium sulfide (GaS:Nd) single crystals was measured from 10 K to room temperature with various heating rates between 0.2 and 1.0 K/sec. Two peaks centered at 70.9 K and 116.0 K were observed when using a heating rate of 0.8 K/sec. Initial rise and curve fitting methods were used to obtain information on trap activation energies. Activation energies of 94 and 216 meV were found for two analyzable peaks. The heating rate dependencies of TL intensities revealed that one of the observed peaks showed normal behavior according to the one trap-one recombination model, whereas the other model showed anomalous heating rate behavior. TL experiments were also carried out at different illumination temperatures from 10 to 32 K; maximum peak temperature remained almost the same at various illumination temperatures. This behavior indicated that the revealed trapping centers are single, discrete levels. The TL glow curves of undoped GaS crystals were also investigated and the effect of Nd doping on the TL characteristics of crystals is discussed in the manuscript.Article Citation - WoS: 3Citation - Scopus: 3Optical and Photoelectrical Properties of Tlinsse Layered Single Crystals(Elsevier Gmbh, 2018) Gasanly, N.; Guler, I.; 101531; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya ÜniversitesiOptical and electrical properties of TlInSSe layered single crystals have been studied by means of transmission, reflection and photoconductivity measurements. Transmission and reflection experiments have been carried out from 540 to 1000 nm at room temperature. Derivative analysis was applied to both transmission and reflection spectra and indirect band gap energy was found as 2.06 eV. Photoconductivity measurements have been performed in the temperature range from 245 to 300 K and in the voltage range from 10 to 80 V. From the temperature-dependent photoconductivity measurements, the observed single peak shifted to higher wavelengths with increase of temperature. The increase of photoconductivity with temperature is due to the increase in the mobility of photocarriers that can be explained by Bube model. From X112 method, room temperature indirect band gap of the crystal was also found as 2.06 eV. From voltage-dependent photoconductivity measurements, the peak maximum increased linearly with increase of voltage because of increase of the mobility of charge carriers. Dark current-voltage characteristic of TlInSSe crystal showed the ohmic behavior that means space charge limited current did not exist in the crystal. From the photocurrent with different illumination intensity analysis, the supralinear photoconductivity associated with the two center model was found. (C) 2017 Elsevier GmbH. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 8Thermoluminescence in Gallium Sesquisulfide Single Crystals: Usual and Unusual Heating Rate Dependencies(Elsevier Gmbh, 2018) Isik, M.; Gasanova, L.; Mahammadov, A.; Gasanly, N.; Guler, I; 101531; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya ÜniversitesiThermoluminescence (TL) experiments were conducted for Ga2S3 crystals to obtain information about trapping parameters. TL measurements were performed from 10 to 300 K with varying heating rates in the range of 0.2-0.8 K/s. Two TL glow peaks centered at 44K (peak A) and 91 K (peak B) were observed at heating rate of beta=0.5 K/s. For peak A, TL intensity decreased whereas that for peak B increased with elevating the heating rates that means anomalous heating rate occurred for peak B. TL glow curves were analyzed using initial rise method to find activation energies of traps. Distribution of trap centers was investigated using T-max - T-stop method. Quasi-continuous distributions with increasing activation energies from 40 to 135 meV and 193 to 460 meV were attributed to trap centers A and B, respectively. (C) 2018 Elsevier GmbH. All rights reserved.
