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Article Citation - WoS: 5Citation - Scopus: 5Low-Temperature Thermoluminescence in Layered Structured Ga0.75in0.25< Single Crystals(Elsevier Science Sa, 2012) Isik, M.; Bulur, E.; Gasanly, N. M.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. The capture cross sections and attempt-to-escape frequencies of the defect centers were also found using the curve fitting method under the light of theoretical predictions. The first order kinetics for the observed glow curve was revealed from the consistency between the theoretical predictions for slow retrapping and experimental results. Another indication of negligible retrapping was the independency of peak position from concentration of carriers trapped in defect levels. (C) 2012 Elsevier B.V. All rights reserved.Article Low Temperature Thermoluminescence of Quaternary Thallium Sulfide Tl4inga3<(indian Assoc Cultivation Science, 2015) Delice, S.; Isik, M.; Bulur, E.; Gasanly, N. M.Thermoluminescence measurements have been carried out on Tl4InGa3S8 single crystals in the temperature range of 10-300 K at various heating rates. The observed thermoluminescence spectra have been analyzed applying many methods like curve fitting, initial rise, peak shape and heating rate methods. Thermal cleaning method has been performed on the observed thermoluminescence glow curve to separate the overlapped peaks. Three distinctive trapping centers with activation energies of 13, 44 and 208 meV have been revealed from the results of the analysis. Heating rate dependence and traps distribution investigations have been also undertaken on the most intensive peak. The thermoluminescence mechanisms in the observed traps have been attributed to first order kinetics (slow retrapping) on the strength of the consistency between theoretical assumptions for slow retrapping process and experimental outcomes.Article Citation - WoS: 12Citation - Scopus: 13Low-Temperature Thermoluminescence in Tlgas2 Layered Single Crystals(Elsevier, 2013) Isik, M.; Bulur, E.; Gasanly, N. M.Thermoluminescence (TL) measurements have been carried out on TlGaS2 layered single crystals in the temperature range of 10-300 K. After illuminating with blue light (similar to 470 nm) at 10 K, TL glow curves exhibited peaks around 23, 36, 58, 75 and 120 K when measured with a heating rate of 0.8 K/s. The observed peaks were analyzed using curve fitting, initial rise, and peak shape methods to determine the activation energies of the associated defect centers. Analyses have revealed the presence of five defect centers with activation energies of 13, 27, 87, 94 and 291 meV. The results of all methods were found to be in good agreement with each other. The consistency between the theoretical predictions for slow retrapping and experimental results showed that the retrapping process for the observed centers was negligible. The independence of peak position from concentration of carriers trapped in defect levels was also another indication of negligible retrapping. The dependence of TL glow curves on heating rate and distribution of traps was also studied. (C) 2012 Elsevier B.V. All rights reserved.
