Highly efficient yellow and white organic electroluminescent devices doped with 2,8-di(t-butyl)-5,11-di[4-(t-butyl)phenyl]-6,12-diphenylnaphthacene

Abstract

We describe the applications of a sterically-hindered yellow dopant, $2,8\text{-}di\left(t\text{-}\mathrm{butyl}\right)\text{-}5,11\text{-}di\left[4\text{-}\left(t\text{-}\mathrm{butyl}\right)\mathrm{phenyl}\right]\text{-}6,12$ -diphenylnaphthacene ($\mathrm{TBRb}$ ) which, when compared to 5,6,11,12-tetraphenylnaphthacene $\left(\mathrm{Rb}\right)$ in either tris(8-hydroxyquinolinato)aluminum or $1,4\text{-}bis\left[N\text{-}\left(1\text{-}\mathrm{naphthyl}\right)\text{-}{N}^{\prime }\mathrm{-phenylamino}\right]-4,4^{\prime }$ diamine (NPB) as host emitter, shows a 50%–34% increase in luminance efficiency over that of $\mathrm{Rb}$ device without significantly affecting its color. In addition, we have incorporated the $\mathrm{TBRb}$ doped yellow NPB emitter into the two-element white organic light-emitting diodes based on $p\text{-}bis\left(p\text{-}N,N\text{-}di\text{-}\mathrm{phenyl}\text{-}\mathrm{aminostyryl}\right)$ benzene doped $2\text{-}\mathrm{methyl}\text{-}9,10\text{-}di\left(2\text{-}\mathrm{naphthyl}\right)$ anthracene sky-blue emitter which improved the luminance efficiency by 44% over that of $\mathrm{Rb}$ to $12.8\mathrm{cd}∕\mathrm{A}$ and $4.3\mathrm{lm}∕\mathrm{W}$ at $20\mathrm{mA}∕{\mathrm{cm}}^2$ with ${\mathrm{CIE}}_{x,y}=\left[0.31,0.38\right]$ .