Thermally stimulated current by charge transfer

A peak at high temperature in a thermogram of thermally stimulated depolarization current (TSDC) of an electret of polyethylene-terephthalate is explained with space charge transfer. Electron and/or holes released from traps make space charge in transport state which is assumed to be of a hopping nature. A concept of thermally stimulated mobility is applied to this process. Transition between trap and transport state, and charge transfer in the latter states are described with simultaneous differential equations. We solve these equations numerically and adjust parameters to make a calculated peak reproduce an observed one as well as possible.