ORGANIC ELECTROLUMINESCENT DEVICES WITH IMPROVED STABILITY

Highly stable organic electroluminescent devices based on vapor-deposi ted Alq thin films have been achieved. The improvement in stability is derived from several factors including: (1) a multilayer thin-film st ructure with a CuPc stabilized hole-injection contact, (2) a hole-tran sport diamine layer using a naphthyl-substituted benzidine derivative, and (3) an ac drive wave form. These emissive devices have shown an o perational half-lifetime of about 4000 h from an initial luminance of 510 cd/m(2). (C) 1996 American Institute of Physics.