1201903-44-7Relevant academic research and scientific papers
Phosphazene-based host materials for the use in blue phosphorescent organic light-emitting diodes
Schroegel, Pamela,Hoping, Matthias,Kowalsky, Wolfgang,Hunze, Arvid,Wagenblast, Gerhard,Lennartz, Christian,Strohriegl, Peter
, p. 4947 - 4953 (2011)
We present a series of low-molecular-weight materials based on cyclic phosphazenes for the use as host materials in blue phosphorescent organic light-emitting diodes. Substituted phenyl rings are attached to the central phosphazene ring either via phosphorus-oxygen bonds to yield phenoxy-substituted derivatives or via direct phosphorus-carbon bonds to yield phenyl-substituted derivatives. The phenoxy substituted cyclic phosphazenes were prepared by nucleophilic substitution of the six chlorine atoms in hexachlorocyclotriphosphazene with phenoxy groups, whereas the phenyl substituted cyclic phosphazenes were formed in a cyclocondensation reaction of three equivalents of substituted phosphinic amides. The phenyl substitution leads to materials with superior thermal properties compared to the phenoxy substitution. Because of the nonconjugated linkage to the phosphazene core, the host materials have very high triplet energies of more than 3 eV. In an OLED device using one compound as host for the saturated blue phosphorescent emitter Ir(dbfmi), a peak power efficiency of 7.6 lm W-1 and a peak luminance of 5000 cd m-2 were achieved.
CYCLIC PHOSPHAZENE COMPOUNDS AND USE THEREOF IN ORGANIC LIGHT EMITTING DIODES
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Page/Page column 17, (2011/08/03)
An organic light-emitting diode comprising at least one cyclic phosphazene compound, a light-emitting layer formed from at least one matrix material and at least one emitter material, wherein the at least one matrix material comprises at least one cyclic
