Thermal stability of bulk p-CdTe

The conductivity and Hall effect were measured in p-type CdTe subjected to thermal changes in the range of 30 °C - 180 °C with the aim to explore the stability of electric properties at such conditions. It was observed that thermal changes often implicate an anomalous behavior of the hole density characterized by reversible decrease/increase in a heating/cooling regime. We explained this anomaly by a transfer of fast diffusing donors between Te inclusions and the bulk of the sample. Sodium and potassium were determined by the Secondary Ion Mass Spectroscopy (SIMS) as the most probable diffusing species. Theoretical model based on this premise was built up and successfully applied to experimental data.