abstract |
The present invention is directed to a class of blue emitting materials, that, when placed in EL devices with an emitter layer and a hole transporter layer, provide EL devices that emit white light. The blue-emitting material has a non-polymeric molecular structure that comprises a five or six-membered heterocyclic moiety selected from the groups consisting of oxazole, imidazole, quinoline and pyrazine with at least three organic substituents pendant thereto. The blue-emitting materials of the present invention have certain characteristics that allow them to be formed into films with advantageous properties. The films formed from these materials are amorphous (i.e they have a crystal size less than about 1000 Å). The thickness of the films of the blue-emitting material is less than 600 Å in the devices of the present invention. |