Determination of deep trapping center parameters in as-grown Tl2Ga2S3Se layered crystals

Thermally stimulated current measurements were carried out on as-grown Tl2Ga2S3Se layered single crystals. The investigations were performed in temperatures ranging from 10 to 320 K with heating rates of 0.6-1.2 K s(-1). The analysis of the data revealed the hole trap level located at 498 meV. The activation energies of the traps have been determined using various methods of analysis, and they agree with each other. The calculation for these traps yielded 2.1 x 10(-18) cm(2) for capture cross-section and 2.3 x 10(9) cm(-3) for the concentration. It was concluded that in this center retrapping was negligible, as confirmed by the good agreement between the experimental results and the theoretical predictions of the model that assumes slow retrapping. (C) 2009 Elsevier Masson SAS. All rights reserved.