Thermally Stimulated Currents under the Condition of Persistent Internal Polarization

A new method is proposed for direct determination of the trapping levels which are responsible for internal polarization in semiconductors. The method is based on the fact that internal polarization, i. e. the internal field, becomes important at low temperatures. In the presence of the internal field, the trapping levels are then investigated by the thermally‐stimulated‐current method. The internal field affects the temperature dependence of the thermally stimulated current. The thermally stimulated current shows a quadratic dependence on carrier concentration in the conduction band. This is the reason for the contraction of the thermally stimulated current maxima and the improvement in their separation.