High‐Purity‐Blue and High‐Efficiency Electroluminescent Devices Based on Anthracene

Abstract

AbstractNovel 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‐diphenylstyryl 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 (α‐NPD)/BDSA/tris(9‐hydroxyquinolinato)aluminum (Alq3)/LiF/Al device shows a narrow emission band with a full width at half maximum (FWHM) of 55 nm and a λmax = 453 nm. The FWHM of the ITO/CuPc/α‐NPD/BTSA/Alq3/LiF/Al device is 53 nm, with a λmax = 436 nm. 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.