Highly efficient white polymer light-emitting devices based on wide bandgap polymer doped with blue and yellow phosphorescent dyes.

We realize high luminous efficiency (LE) in white polymer light-emitting devices by employing a wide bandgap polymer P36HCTPSi as host and introducing a blue-yellow two-color system for obtaining white emission. Phosphorescent dopants bis[(4,6-difluorophenyl)pyridinato-N,C(2)]-(picolinato)iridium(III) (FIrpic) and iridium(III) bis(2-(9,9'-spirobi[fluorene]-7-yl)pyridine-N,C(2')) acetylacetonate [Ir(SBFP)(2) (acac)] were used as blue and yellow emitters, respectively. Electroluminescent spectra and LE were both affected by Ir(SBFP)(2)(acac) concentration; the device with low concentration (0.4 wt.%) showed white emission with a LE of 24.1 cd/A at 1000 cd/m(2), while the one with high concentration (4 wt.%) emitted yellowish-white light with a higher LE of 47.3 cd/A at 1000 cd/m(2).