Charge relaxation in conducting dielectric films with shallow and deep traps

A nonsteady-state boundary-value problem of the relaxation of a charge injected into a dielectric film is solved analytically with allowance for the film conductivity and capture of charge carriers by traps having a finite emptying rate. The one-and two-zone modes of charge relaxation are considered. The obtained general expressions reduce to earlier published formulas derived in particular cases. Numerical calculations and an analysis of the experimental data available in the literature on the electret state of oxide films deposited on metal substrates confirm the applicability of the proposed model of dielectric relaxation.