Thermally stimulated current analysis of shallow levels in TlGaS2 layered single crystals

We have carried out thermally stimulated current measurements on as-grown TlGaS2 layered single crystals in the temperature range of 10–60 K with various heating rates. We found experimental evidence for the presence of three trapping centres in TlGaS2, located at 6, 12 and 26 meV. We have determined the trap parameters using various methods of analysis, and these agree well with each other. The retrapping process is negligible for these levels, as confirmed by the good agreement between the experimental results and the theoretical predictions of the model that assumes slow retrapping.