Determination of trapping center parameters of Tl2InGaS4-layered crystals by thermally stimulated current measurements

2006-06-29
Mogaddam, Nader A. P.
Yuksek, N. S.
Hasanlı, Nızamı
Ozkan, H.
We have carried out thermally stimulated current measurements on as-grown Tl2InGaS4-layered single crystals in the low temperature range 10-60 K with different heating rates. We found experimental evidence for the presence of two shallow hole trapping centers with activation energies of 4 and 10 meV. We have determined the trap parameters using various methods of analysis, and these agree with each other. Their capture cross-sections have been found to be 6.5 x 10(-26) and 4.0 x 10(-25) cm(2), respectively, and their concentrations are 2.1 x 10(12) and 6.5 x 10(12) cm(-3), respectively. It is concluded that in these centers retrapping is negligible, as confirmed by the good agreement between the experimental results and the theoretical predictions of the model that assumes slow retrapping.