Linear Models and the Kinetics of Thermally Activated Currents and Voltages

Abstract

Experimental results from thermally activated measurements can be analyzed by different methods. In view of the difficulty of obtaining precise solutions of the differential equations describing the transport and trapping of charge carriers in solid dielectrics, various linearized theories have been developed. In the present paper the isothermal theory of conventional models is generalized and a nonisothermal model theory is established. Current transients generated by heating in short‐circuit and voltage‐transients generated by heating in open‐circuit are discussed. It is found that under nonisothermal conditions the concept of equivalency of models must be severely restricted and that the assumptions of charge invariance and absence of current reversals, implicit in many existing theories, cannot be taken for granted. One concludes that the interpretation of thermal activation measurements without the knowledge of the structure of the system under consideration and the underlying physical mechanism leads to ambiguities.