A three-spectrum white OLED using green and new red phosphorescent sensitizers

Abstract

We develop a three-spectrum white organic light-emitting diodes (WOLED) with blue phosphor-sensitized electrofluorescent, green and new red electrophosphorescent emissions. The green phosphorescent sensitizers are bis[5-(trifluoromethyl)-2-(4-fluorophenyl)pyridine]iridium(III)acetylacetonate (Ir-2h) or Bis(2-phenylpyridine) iridium(III)3-Methyl-2,4-pentanedione (Ir(ppy)₂mac), and the new red phosphorescent sensitizer is a phenyl-qoinazoline framework organo-iridium complex. The RGB peaks of WOLED with Ir-2h are at a wavelength of 440nm, 516nm, and 633nm, respectively. However, The RGB peaks of WOLED are at a wavelength of 440nm, 550nm, and 625nm, respectively, when the green phosphorescent sensitizer is replaced by Ir(ppy)₂mac. Besides, the peak at a wavelength of 550nm is broader than the former. Therefore, The former WOLED of RGB spectra are the most distinct than the later one. The former WOLED has efficiency of 3.3 lm/W (7.15Cd/A) at 1000 Cd/m², and CIE coordinates of (0.32, 0.35). It is good suitability to use in OLED displays based on RGB color filters and full-color LCD backlights.