We have developed a highly efficient and stable blue organic electroluminescent (EL) device based on a blue fluorescent styrylamine dopant, p-bis(p-N,N-diphenyl-aminostyryl)benzene, in a morphologically stable high band-gap host material, 2-methyl-9,10-di(2-naphthyl)anthracene, which achieved an EL efficiency of 9.7cd∕A and 5.5lm∕W at 20mA∕cm2 and 5.7 V, with Commission Internationale d’Eclairage coordinates of (x=0.16,y=0.32). The blue-doped device achieved a half-decay lifetime (t1∕2) of 46 000 h at an initial brightness of 100cd∕m2.

We have synthesized a new green fluorescent dopant C-545P having incorporated five strategically placed "methyl" steric spacers on the julolidyl ring system. C-545P has good thermal properties and photostability, and when fabricated as a dopant in an Alq(3)-hosted OLED device, it shows notable improvement in luminance efficiency and is more resistant to concentration quenching than C-545T, particularly in the doping concentration range between 1 and 2% v/v, while achieving comparable device stability. [structure: see text]

Spiro-FPA, a novel blue emitter, in which two identical anthracene luminophores are linked orthogonally around a spirobifluorene core, has been synthesized and characterized. The introduction of a spiro linkage into the structure of spiro-FPA leads to a reduction in crystallization tendency and an increase in glass transition temperature relative to the monomeric units. In addition, the tetrahedral nature of the carbon atom at the spiro center preserves the optical and electrochemical characteristics of the pristine anthracene units. As demonstrated by AFM measurements, high-quality amorphous films of spiro-FPA with good morphological stability can be prepared by vapor deposition. Organic EL devices constructed using a 1.0-wt % TBP-doped spiro-FPA emitting layer produce bright blue emissions with a high luminescence efficiency of 4.9 cd/A (2.07 lm/W).

No abstract

No abstract