화학공학소재연구정보센터
Advanced Functional Materials, Vol.15, No.11, 1799-1805, 2005
High-purity-blue and high-efficiency electroluminescent devices based on anthracene
Novel blue-light-emitting materials, 9,10-bis(1,2-diphenyl styryl)anthracene (BDSA) and 9,10-bis(4'-triphenylsilylphenyl)anthracene (BTSA), which are composed of an anthracene molecule as the main unit and a rigid and bulky 1,2-diphenyistyryl or triphenylsilylphenyl side unit, have been designed and synthesized. Theoretical calculations on the three-dimensional structures of BDSA and BTSA show that they have a non-coplanar structure and inhibited intermolecular interactions, resulting in a high luminescence efficiency and good color purity. By incorporating these new, non-doped, blue-light-emitting materials into a multilayer device structure, it is possible to achieve luminance efficiencies of 1.43 lm W-1 (3.0 cd A(-1) at 6.6 V) for BDSA and 0.61 lm W-1 (1.3 cd A(-1) at 6.7 V) for BTSA at 10 mA cm(-2). The electroluminescence spectrum of the indium tin oxide (ITO)/copper phthalocyanine (CuPc)/1,4-bis[(1-naphthylphenyl)-amino]biphenyl (alpha-NPD)/BDSA/tris(9-hydroxyquinolinato)aluminum (Alq(3))/LiF/Al device shows a narrow emission band with a full width at half maximum (FWHM) of 55 nm and a lambda(max) = 453 nm. The FWHM of the ITO/CuPc/alpha-NPD/BTSA/Alq(3)/LiF/Al device is 53 nm, with a lambda(max) = 436 rim. Regarding color, the devices showed highly pure blue emission ((x,y) = (0.15,0.09) for BTSA, (x,y) = (0.14,0.10) for BDSA) at 10 mA cm(-2) in Commission Internationale de l'Eclairage (CIE) chromaticity coordinates.