New bipolar host materials for high performance of phosphorescent green organic light-emitting diodes?

RSC Advances Pub Date: 2015-03-20 DOI: 10.1039/C5RA04593B

Abstract

We report a series of four bipolar host materials with indenocarbozole and biphenyl pyrimidine moieties for efficient phosphorescent green organic light-emitting diodes (OLEDs). All four host materials possess excellent electro-optical properties as well as good thermal and morphological stability due to their high glass transition temperature of 129 °C and decomposition temperature of 363–401 °C. The new materials also show good triplet energy of 2.76 eV and excellent charge carrier transport properties. The fabricated OLED device with 11-[3-(2,6-diphenyl-pyrimidin-4-yl)-phenyl]-12,12-dimethyl-11,12-dihydro-11-aza-indeno[2,1-a]fluorene (mDPPICz1) as green host shows maximum current and power efficiency as high as 75.8 cd A?1 and 87.1 lm W?1 at 1000 cd m?2, and an almost ideal external quantum efficiency of 21.7%.

Graphical abstract: New bipolar host materials for high performance of phosphorescent green organic light-emitting diodes
Recommended Literature