Trapping center parameters in In6S7 crystals

Thermally stimulated current measurements were carried out on In6S7 single crystals in the temperature range of 10-225 K with a constant heating rate of 0.8 K/s. The study of trapping centers was accomplished by the measurements of current flowing along the c-axis of crystals. The analysis of the glow curve according to various methods, such as curve fitting, initial rise and peak shape methods, gives results in good agreement with each other and revealed two trapping centers in In6S7 with activation energies of 157 and 290 meV. Their capture cross sections have been determined as 7.5×10−23 and 7.1×10−20 cm2,respectively. The good agreement between the experimental results and the theoretical predictions of the model that assumes slow retrapping has confirmed that retrapping is negligible in these centers.