White light-emitting organic electroluminescent device base on a new orange organometallic iridium complexes

摘要

We develop the white organic light-emitting diodes (WOLEDs) with a new orange electrophosphorescent emission, and the blue electrofluorescent or electrophosphorescent sensitizer. The new orange phosphorescent sensitizer is the thieno-pyridine framework organo-iridium complexes (PO-01). The blue phosphor-sensitized electrofluorescent is 4,4'-Bis(9-ethyl-3-carbazovinylene)-1,1'- biphenyl (DSA) doped into 4,4'-Bis(2,2-diphenyl-ethen-1-yl) diphenyl (DPVBi). Beside, the blue phosphorescent sensitizer is Bis(3,5-difluoro-2-(2-pyridyl)phenyl-^s(2-carboxypyridyl)iridium (FirPic). The Device Type I of WOLED based on the PO-01 and the DSA doped into DPVBi has an efficiency of 5.7 lm/W (10.6Cd/A) at 500 Cd/m~2, a CIE coordinates of (0.33, 0.31), and a CRI of 71. However, the Device Type Ⅱ of WOLED has an efficiency of 5.5 lm/W (10.3Cd/A) at 500 Cd/m~2 and a CIE coordinates of (0.30, 0.42), while the FirPic replaces the DPVBi doped with DSA. The spectra of the Device Type Ⅱ and I both response insensitive to drive current. Nevertheless, the Device Type Ⅰ relatively achieves a balanced whit emission with CIE coordinates of (0.33, 0.33). They are good suitability to use in OLED lighting and full-color LCD backlights.