Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2012-01-01

Journal: DYES AND PIGMENTS

Included Journals: EI、SCIE

Volume: 92

Issue: 1

Page Number: 674-680

ISSN: 0143-7208

Key Words: Thieno-[3,4-b]-pyrazine; Red; Organic light-emitting diodes; Solution processing; Vacuum evaporation; Large Stokes shift

Abstract: Two novel red-emitting thieno-[3,4-b]-pyrazine-cored molecules with phenyls (TP) or polyphenyls (Mullen type dendron, DTP) as peripheral groups were designed and synthesized. They have large Stokes shifts over 100 nm. DTP is thermally stable with decomposition temperature up to 458 degrees C. More importantly, it is amorphous with a remarkably high glass transition temperature of 262 degrees C. DTP can be made into thin films either by solution method or vacuum evaporation. Red OLEDs were fabricated using either spin coated or vacuum evaporated DTP film as emitting layer. The evaporated device exhibited a maximum brightness of 1753 cd m(-2) and a luminous efficiency of 0.74 cd A(-1), which are among the best data ever reported for thieno-[3,4-b]-pyrazine derivatives so far. In contrary, TP failed to produce satisfied red emission in its evaporated OLEDs. (C) 2011 Elsevier Ltd. All rights reserved.