Highly efficient and color-tuning electrophosphorescent devices based on CuI complex

Highly efficient electrophosphorescence from organic light-emitting devices based on a Cu-I complex, [Cu(DPEphos)(Dicnq)]BF4 (DPEphos=bis[2-(diphenylphosphino)phenyl]ether and Dicnq=6,7-Dicyanodipyrido[2,2-d:2('),3(')-f] quinoxaline), doped into 4,4(')-N,N-'-dicarbazole-biphenyl is demonstrated. The performances of these devices fabricated by vacuum vapor deposition technique are among the best reported for devices incorporating Cu-I complexes as emitters. A low turn-on voltage of 4 V, a maximum current efficiency up to 11.3 cd/A, and a peak brightness of 2322 cd/m(2) were achieved, respectively. The phosphorescent operating mechanism of organic light-emitting devices based on Cu-I complex was discussed. Electroluminescent colors can be tuned ranging from green-yellow to orange-red region, and its band tail at longer wavelength can cover near infrared. (c) 2006 American Institute of Physics.