Phosphoescent OLED for full colour display

摘要

A phosphorescent organic light emitting device (OLED) is characterised by a cathode comprising an alkaline earth metal oxide. The cathode includes an electron injecting layer 20 and reflective layer 22. The electron injecting layer 20 is made of an alkaline earth metal oxide such as Barium oxide while the reflective layer 22 preferably comprises aluminium or silver. An organic light emissive layer 18 is formed in direct contact with the electron injecting layer 20. The light emissive layer 18 may comprise an organic semiconductor host in which an organic phosphorescent dye is dispersed. Phosphorescent OLEDs of different colours can be arranged to form a full colour display using inkjet printing techniques.