Thermally stimulated currents in amorphous solids due to complex heating regimes

The paper contains a theoretical description of thermally stimulated currents (TSCs) in amorphous solids. Earlier approximate formulas for TSCs are extended to the cases of delayed and step sample heating. TSC features characteristic for these heating schemes can be attributed to the non-linear dependence of the demarcation energy level on temperature. In particular, the initial TSC rise has a thermally activated character, with the activation energy equal to the demarcation energy at the onset of sample heating. The accuracy of the obtained formulas is verified by numerical calculations of TSCs for exponential trap distribution. The predicted TSC features are shown to be consistent with those established experimentally for amorphous hydrogenated silicon.