1 research outputs found
New Bipolar Host Materials for Realizing Blue Phosphorescent Organic Light-Emitting Diodes with High Efficiency at 1000 cd/m<sup>2</sup>
New host molecules such as 9-(6-(9<i>H</i>-carbazol-9-yl)pyridin-3-yl)-6-(9<i>H</i>-carbazol-9-yl)-9<i>H</i>-pyrido[2,3-<i>b</i>]indole (pPCB2CZ) and 9-(6-(9<i>H</i>-carbazol-9-yl)pyridin-2-yl)-6-(9<i>H</i>-carbazol-9-yl)-9<i>H</i>-pyrido[2,3-<i>b</i>]indole (mPCB2CZ) were designed
and synthesized for blue phosphorescent organic light-emitting diodes
(PhOLEDs). The glass transition temperatures of two host molecules
were measured higher than 120 °C, and the identical triplet energies
were determined to be 2.92 eV for both molecules. The bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III)
(FIrpic)-doped mPCB2CZ-based PhOLED exhibited practically useful driving
voltage of 4.8 V in a simple organic three layer device configuration
which has a smaller number of interfaces in conventional multilayer
PhOLEDs. Also, the high quantum efficiency of 23.7% is reported at
the practically useful brightness value of 1000 cd/m<sup>2</sup>