A phenomenological theory of double injection with trapping

Abstract

A phenomenological theory of double injection into an insulator with traps is derived under the injected plasma approximation. Four probable trap configurations are considered: discrete hole and electron traps, discrete hole and exponential electron traps, exponential hole and discrete electron traps, and exponential hole and electron traps. The traps are assumed to act as recombination centres. The large range of possible j-V relations which emerges from these models is delineated. By allowing the recombination radiation to cause photodetrapping the scaling law (j/d) = f(V/d²) can be violated, explaining a common feature of experimental work on anthracene. An exact calculation is used to confirm the theory for a simple case.