Electroluminescence and enhanced double-injection in crystals of anthracene

Abstract

A study of the double injection currents and recombination electroluminescence in anthracene crystals grown under different inert atmospheres is reported. The results are interpreted in terms of the injection of holes by a field-enhanced tunnelling through a surface barrier. An equation is proposed which satisfactorily describes the current-voltage characteristics over a wide range, and the measured temperature dependence of the current is also in accord with the proposed mechanism.

The electroluminescence spectrum from certain crystals showing a broad structureless emission extending to long wavelengths is probably associated with the presence of specific orientations of pairs of anthracene molecules arising from structural imperfections. The intensity of this emission is smaller in relation to the main emission peaks than that previously reported, and shows no direct correlation with the nature of the particular inert gas employed during crystal growth.