DOUBLE INJECTION AND ELECTRO-LUMINESCENCE IN PARA-TERPHENYL SINGLE-CRYSTALS

Double injection currents in p-terphenyl are followed by light emission from decaying singlet excitons produced by the recombining electron-hole pairs. Only one singlet exciton is produced out of similar 100 recombinations, the other recombinations are non-radiative. The current densities with gold and Na-Hg amalgam as hole and electron injecting contacts, respectively, approached the limit of volume-controlled currents, but were limited to well defined spots covering only 10** minus **3-10** minus **4 of the contacts area.