Xerographic depletion discharge versus injection for modelling the surface potential decay in insulators

The surface potential dark decay after corona charging of inorganic amorphous semiconductors (a-Se, a-Se_1-xTe_x , a-As₂Se₃) and organic polymers (high-density polyethylene, P(AN-MA)) follows in many cases a power-law time dependence with different exponents in two distinct time domains separated by a characteristic time. A careful analysis of experimental data from the literature and original measurements shows, however, that the seemingly identical phenomenology exhibits very different dependences of empirical parameters on field strength and temperature. Is is suggested that a consistent physical interpretation of the measurements is achievable in the case of inorganic semiconductors under the assumption of thermal generation and in the case of polymers with injection of charge carriers