Spirobifluorene/sulfone hybrid: Highly efficient solution-processable material for UV-violet electrofluorescence, blue and green phosphorescent OLEDs

A high efficient UV-violet emission type material bis[4-(9,9'-spirobifluorene-2-yl)phenyl]sulfone (SF-DPSO) has been synthesized by incorporating electron deficient sulfone and morphologically stable spirobifluorene into one molecule. The steric and bulky compound SF-DPSO exhibits an excellent solid state photoluminescence quantum yield (Phi(PL) = 92%), high glass transition temperature (T-g = 211 degrees C) and high triplet energy (E-T = 2.85 eV). In addition, the uniform amorphous thin film could be formed by spin-coating from its solution. These promising physical properties of the material made it suitable for using as UV-violet emitter in non-doped device and appropriate host in phosphorescent OLEDs. With SF-DPSO as an emitter, the non-doped solution processed device achieved an efficient UV-violet emission with the EL peak around 400 nm. By using SF-DPSO as a host, solution processed blue and green phosphorescent organic light emitting diodes showed a high luminous efficiency of 13.7 and 30.2 cd A(-1), respectively. (C) 2014 Elsevier B.V. All rights reserved.