Estimation of the parameters of charge carriers in polymers in the vicinity of the threshold of thermally stimulated switching

The temperature dependences of the parameters of charge carriers in thin films of an electroactive poly(diphenylenephthalide) polymer are investigated in the range preceding the thermally stimulated electronic switching (110–400 K). The thermally stimulated current spectra and current-voltage characteristics are measured in the same temperature range. The parameters of charge carriers are estimated in the framework of the model of injection currents limited by the space charge. It is revealed that the charge carrier mobility decreases with an increase in the temperature in the range from 110 to 400 K. A correlation between the temperature behavior of the current-voltage characteristics and the thermally stimulated current spectra is established. The possible contribution of the Pool-Frenkel effect is considered, and the inference is made that the electric field plays an important role in the thermally stimulated electronic switching.