It was observed that the electrical resistance of n-CuIn3Te5 single crystal varied with time in the course of measurement. The current intensity and the potential drop across the sample decreased by up to 14% and 0.3%, respectively, after 300s when a constant potential was applied. The single crystal does not obey Ohm's law. The current intensity plot was fitted to a decay exponential and linear functions in the 0 to 45s and 45 to 300s ranges, respectively. The resistance increase of the CuIn3Te5 single crystal could be due to the high concentration of intrinsic vacancies existing in the crystal structure. The experimental measurements were analysed in terms of a hypothesis of ion migration via structural vacancies. The Cu+ and/or In3+ cations were moved towards the cathode and were deposited in a space charge region. The space-charge-region/electrode interface was modelled as an ideal capacitor and the arrival of ions produces a potential change in this region that was related to the current intensity and the potential drop across the sample.

Ion Migration in CuIn3Te5 Single Crystal. R.Díaz: Journal of Physics D, 2007, 40[21], 6522-6