The theory of transient currents in dielectric layers at a limited level of single injection is suggested. As a result of the analysis six mechanisms of the transient process are revealed, that lead to a stationary space‐charge‐limited current. The conditions of existence and characteristic features of each of the mechanisms are ascertained. For all stages of the transient process a complete analysis of these mechanisms typical for the strong injection case, is performed. Analytical expressions for the time behaviour of the total current, total charge, space‐charge centroid, and electric field strength on the injecting interface, are obtained they correspond to the results of exact (numerical) solution of the general problem.
A relation between the character of charge redistribution in a dielectric layer and temporal variation of the current is revealed by a numerical analysis of the mathematical model of transient single injection‐current in the presence of trapping. Three mechanisms are singled out for the case of fast trapping and weak injection, determining the charge distribution throughout the layer. Analytical time dependences of the transient current, space charge, and space charge centroid are obtained while analyzing peculiarities of the mechanisms. A technique is suggested for the determination of dielectric layer parameters, using measurements of time constants characteristic of fast trapping and weak injection cases.
The main influence on the transient process is shown to be exerted by the initial trapped space charge entering the dielectric before the onset of injection by carrier diffusion. This charge leads to a sharp decrease of the transient current and to a superlinear dependence of its value on the applied voltage in comparison with the case without diffusion. Approximate analytical solutions for the initial charge distribution and the transient current behavior are derived. They correspond to the results of an exact (numerical) solution of the general problem. Criteria for the validity of the diffusionless approximation are found.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.