Long-lifetime, high-efficiency white organic light-emitting diodes with mixed host composing double emission layers

Yung-Cheng Tsai, Jwo-Huei Jou
2006 Applied Physics Letters  
A long-lifetime, high-efficiency white organic light-emitting diode was fabricated with a mixed host in one of double emission layers. The first layer comprised yellow rubrene doped in a mixed host consisting of 50% N , NЈdiphenyl-N , NЈ-bis-͑1-naphthyl͒-1,1Ј-biphenyl-4-4Ј-diamine ͑NPB͒ and 50% 2-͑t-butyl͒-9,10-bis͑2Ј-naphthyl͒anthracene ͑TBADN͒. The second layer comprised blue 4,4Ј-bis͓2-͕4-͑N , N-diphenylamino͒phenyl͖vinyl͔ biphenyl doped in TBADN. This device exhibited the longest lifetime,
more » ... longest lifetime, five times that of its pure NPB counterpart. The resulting efficiency was 6.0 lm/ W ͑10.9 cd/ A͒ at 10 mA/ cm 2 , 33% better than that of the NPB counterpart. These improvements were attributable to the mixed-host structure, which effectively dispersed carriers and gave a good charge balance.
doi:10.1063/1.2408663 fatcat:fqcnufye6jb5xk6p3oifv74uzq