Organic electroluminescent devices using alkaline-earth fluorides as an electron injection layer

We investigated the properties of organic electroluminescent (EL) devices u sing alkaline-earth fluorides as an electron injection layer, and found tha t the alkaline-earth fluorides are desirable materials to reduce the turn-o n voltage of the EL devices with Al cathode. In the devices using the fluor ides as the electron injection layer, we found that the turn-on voltage can be associated with electronegativity of metal ion of the fluoride; the flu oride with a low electronegativity metal ion results in lowering the barrie r height at the organic/Al interface and enhanced the electron injection. ( C) 2000 Elsevier Science B.V. All rights reserved.