A wide band gap polymer derived from 3,6-carbazole and tetraphenylsilane as host for green and blue phosphorescent complexes

Abstract

We have synthesized a novel wide band gap polymer P36HCTPSi derived from 3,6-carbazole and tetraphenylsilane by palladium-catalyzed Suzuki coupling reaction. The resultant polymer shows a high glass transition temperature (217 °C) and good thermal stability. The conjugation length of P36HCTPSi is effectively confined because of the δ-Si interrupted polymer backbone. The polymer exhibits a violet emission with a peak at 392 nm in solution, and the band gap estimated from the onset of its absorption is 3.26 eV The high energy emission and wide band gap of P36HCTPSi make it appropriate host for green and blue emission phosphorescent materials. Efficient energy transfers from P36HCTPSi to both fac-tris[2-(2-pyridylkN)-5-methylphenyl]iridium(III) (green emission) and bis[(4,6-difluorophenyl)pyridinato-N,C2]-(picolinato) iridium(III) (blue emission) were observed in photoluminescence (PL) spectra. Highly efficient phosphorescent polymer light-emitting devices were realized by using P36HCTPSi as the host for iridium complexes, the maximum luminous efficiencies for green and blue devices were 27.6 and 3.4 cd/A, respectively. © 2009 Wiley Periodicals, Inc.