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Efficient Deep‐Blue Organic Light‐Emitting Diodes: Arylamine‐Substituted Oligofluorenes
Author(s) -
Gao Z. Q.,
Li Z. H.,
Xia P. F.,
Wong M. S.,
Cheah K. W.,
Chen C. H.
Publication year - 2007
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200700238
Subject(s) - materials science , quantum yield , oled , dopant , thermal decomposition , quantum efficiency , fluorescence , photochemistry , diode , homo/lumo , optoelectronics , suzuki reaction , palladium , doping , nanotechnology , catalysis , molecule , organic chemistry , optics , chemistry , physics , layer (electronics)
Novel deep‐blue‐light‐emitting diphenylamino and triphenylamino end‐capped oligofluorenes were synthesized by double palladium‐catalyzed Suzuki cross‐coupling of dibromo‐oligofluorene with the corresponding boronic acid as a key step. These oligofluorenes exhibit deep‐blue emission (λ em max = 429–432 nm), low and reversible electrochemical oxidation (highest occupied molecular orbital = 5.15–5.20 eV), high fluorescence quantum yield (Φ FL = 0.61–0.93), and good thermal properties (glass‐transition temperature, T g = 99–195 °C and decomposition temperature, T dec > 450 °C). Remarkably, saturated deep‐blue organic light‐emitting diodes, made from these oligofluorenes as dopant emitters, have been achieved with excellent performance and maximum efficiencies up to 2.9 cd A –1 at 2 mA cm –2 (external quantum efficiency of 4.1 %) and with Commission Internationale de l'Éclairage ( x , y ) coordinates of (0.152,0.08), which is very close to the National Television System Committee standard blue.