In:
Chemistry – A European Journal, Wiley, Vol. 17, No. 46 ( 2011-11-11), p. 12994-13006
Abstract:
Blue fluorescent materials with a 2‐(diphenylamino)fluoren‐7‐ylvinylarene emitting unit and tert ‐butyl‐based blocking units were synthesized. The photophysical properties of these materials, including UV/Vis absorption, photoluminescent properties, and HOMO–LUMO energy levels, were characterized and rationalized with quantum‐mechanical DFT calculations. The electroluminescent properties of these molecules were examined through the fabrication of multilayer devices with a structure of indium–tin oxide, 4,4′‐bis{ N ‐[4‐( N,N ‐di‐ m ‐tolylamino)phenyl]‐ N ‐phenylamino}biphenyl, 4′‐bis[ N ‐(1‐naphthyl)‐ N ‐phenylamino]biphenyl, and blue materials doped in 2‐methyl‐9,10‐di(2‐naphthyl)anthracene/tris(8‐quinolinolato)aluminum/LiF/Al. All devices exhibit highly efficient blue electroluminescence with high external quantum efficiency (3.20–7.72 % at 20 mA cm −2 ). A deep‐blue device with Commission Internationale de l’Eclairage (CIE) coordinates of (0.15, 0.11) that uses 7‐[2‐(3′,5′‐di‐ tert ‐butylbiphenyl‐4‐yl)vinyl]‐9,9‐diethyl‐2‐ N ‐(3,5‐di‐ tert ‐butylphenyl)‐2,4‐difluorobenzenamino‐9 H ‐fluorene as a dopant in the emitting layer showed a luminous efficiency and external quantum efficiency of 3.95 cd A −1 and 4.23 % at 20 mA cm −2 , respectively. Furthermore, a highly efficient sky‐blue device that uses the dopant 7‐{2‐[2‐(3,5‐di‐ tert ‐butylphenyl)‐9,9′‐spirobifluorene‐7‐yl]vinyl}‐9,9‐diethyl‐2‐ N,N ‐diphenylamino‐9 H ‐fluorene exhibited a luminous efficiency and high quantum efficiency of 10.3 cd A −1 and 7.7 % at 20 mA cm −2 , respectively, with CIE coordinates of (0.15, 0.20).
Type of Medium:
Online Resource
ISSN:
0947-6539
,
1521-3765
DOI:
10.1002/chem.201100304
Language:
English
Publisher:
Wiley
Publication Date:
2011
detail.hit.zdb_id:
1478547-X
detail.hit.zdb_id:
1231884-X
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