Organic electroluminescent element, illuminator, and display
申请人:KONICA MINOLTA HOLDINGS, INC.
公开号:EP1464691B1
公开(公告)日:2013-10-02
US7485376B2
申请人:——
公开号:US7485376B2
公开(公告)日:2009-02-03
A series of CBP-derivatives as host materials for blue phosphorescent organic light-emitting diodes
作者:Pamela Schrögel、Aušra Tomkevičienė、Peter Strohriegl、Sebastian T. Hoffmann、Anna Köhler、Christian Lennartz
DOI:10.1039/c0jm03321a
日期:——
We report a series of CBP-derivatives with superior thermal and electronic properties for the use as host materials for blue electrophosphorescent organic light emitting diodes. We applied a systematic variation of the substitution pattern in the 2- and 2′-position of the biphenyl unit and the 3- and 6-position of the carbazole moieties. In contrast to the crystalline parent compound CBP, all methyl and trifluoromethyl substituted derivatives show amorphous behaviour. Substitution in the 2- and 2′-position of the biphenyl causes a twisting of the phenyl rings. Hence, the degree of conjugation of the molecules is limited which leads to enlarged triplet energies of approximately 2.95 eV compared to 2.58 eV for CBP. The methyl substitution at the active 3- and 6-position of the pendant carbazole units yields materials with an electrochemically stable behaviour against oxidation.