1548941-63-4Relevant academic research and scientific papers
High-power-efficiency blue electrophosphorescence enabled by the synergistic combination of phosphine-oxide-based host and electron-transporting materials
Gong, Shaolong,Chang, Yi-Lu,Wu, Kailong,White, Robin,Lu, Zheng-Hong,Song, Datong,Yang, Chuluo
, p. 1463 - 1470 (2014/03/21)
A new host material of (4-{1-[4-(diphenylphosphoryl)phenyl]cyclohexyl} phenyl)bis(4-methylphenyl)amine (POPCPA) is designed and synthesized by integrating electron-donating 4,4′-dimethyldiphenylamine unit and electron-accepting diphenylphosphine oxide group into the cyclohexane skeleton. The design strategy endows the host material with a high triplet energy of 2.93 eV, a shallow HOMO level of -5.24 eV, and a bipolar charge transporting feature. In addition, a new electron-transporting (ET) material of 1,3,5-tri[3- (diphenylphosphoryl)phenyl]benzene (TP3PO), which possesses a high triplet of 2.78 eV, a deep HOMO level of -6.40 eV, and a good ET ability, is constructed by the suitable combination of three diphenylphosphine oxide groups and the triphenylbenzene skeleton. These features render these phosphine-oxide-based functional materials ideal for blue phosphorescent organic light-emitting diodes (PhOLEDs). By employing these functional materials, a blue device exhibits low driving voltages of 2.6, 3.6, and 5.4 V at the luminance of 1, 100, and 1000 cd m-2, respectively, and the highest power efficiency (up to 45.3 lm W-1) to date for iridium(III) bis(4′,6′- difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate (FIr6)-based blue PhOLEDs, which is significantly higher than those of the FIr6-based PhOLEDs with n-doped electron-transporting layer or p-i-n structure. These results suggest that the high-power-efficiency blue PhOLEDs can be achieved by elaborate designing of host and electron-transporting materials systematically to suit the blue emitter and emission zone structure.
