Effect of N doping on Tl2Ga2S3Se single crystals: Thermoluminescence characterization of defect centers

Abstract

Thermoluminescence study on nitrogen doped Tl 2 Ga 2 S 3 Se single crystals was achieved by performing the experiments with different stopping temperatures of 10−24 K and various heating rates between 0.4 and 1.2 K/s below room temperature. Thermoluminescence peak with peak maximum temperature of 54 K was detected from the emitted luminescence. Two trap levels were obtained from the observed spectra. Curve fitting and initial rise methods were applied to compute the activation energies and the values of 34 and 70 meV were found. Thermal cleaning process was applied to separate the overlapping peaks and so true energy region of trapping levels was corroborated. Moreover, variation of shape and position of TL curve were studied by investigating the heating rate behavior of trap levels. The best known behavior which the peak maximum temperature increases while the thermoluminescence intensity decreases with raising heating rate was observed. The effect of the N doping on the existed defects was discussed.