| abstract |
An OLED device comprises a cathode, an anode, and has therebetween a light emitting layer (LEL) comprising a phosphorescent emitting compound disposed in a host comprising a mixture of at least one electron transporting co-host which is a benzophenone derivative with a spiro substituent and at least one hole transporting co-host which is a triphenylamine which contains one trivalent nitrogen atom that is bonded only to carbon atoms, at least one of which is a member of an aromatic ring, wherein there is present an electron transporting layer contiguous to the LEL (HBL?) on the cathode side comprising an anthracene or a fluoranthene and wherein there is present an election injecting layer comprising a phenanthroline or a lithium quinolate contiguous to the cathode. |