Novel 4-(2,2-diphenyl-vinyl)-phenyl substituted pyrene derivatives as efficient emitters for organic light-emitting diodes

Two pyrene derivatives (PVPP and TPVPP) bearing 4-(2,2-diphenyl-vinyl)-phenyl side unit were developed for organic light-emitting diodes. Their photophysical, thermal, electrochemical, and electroluminescent properties as well as the film morphologies have been investigated in detail. Both of them exhibit high solid-state quantum yields, good thermal stability, and high glass-transition temperatures in the range of 127-150 degrees C. In particular, it is found that multiple side units can significantly affect the electrochemical properties to improve the electron injection. The LUMO energy level of TPVPP is -2.76 eV, which is very close to that of commonly used electron transport materials. The maximum luminance of OLED devices using TPVPP as an emitter layer is 103835 cd/m(2) with a maximum current efficiency of 5.19 cd/A and a maximum power efficiency of 3.38 lm/W. (C) 2012 Elsevier B.V. All rights reserved.Materials Science, MultidisciplinaryPhysics, AppliedSCI(E)EI3ARTICLE122898-29041