The efficiency enhancement of single-layer solution-processed blue phosphorescent organic light emitting diodes by hole injection layer modification

作者：Yeoh K H^*; Talik N A; Whitcher T J; Ng C Y B; Woon K L

来源：Journal of Physics D: Applied Physics , 2014, 47(20): 205103.

DOI：10.1088/0022-3727/47/20/205103

• perfluorinated ionomer
• PEDOT : PSS
• blue organic light emitting diode (OLED)
• solution-processed method

Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) PEDOT : PSS is extensively used as a hole injection layer (HIL) in solution-processed organic light emitting diodes (OLEDs). The high work function of a HIL is crucial in improving OLED efficiency. The work function of PEDOT : PSS is usually around 5.1-5.3 eV. By adding perfluorinated ionomer (PFI), the work function of PEDOT : PSS has been reported to reach as high as 5.95 eV. We investigated the effects of PFI-modified PEDOT : PSS in a single-layer solution-processed blue phosphorescent OLED (PHOLED). We observed that high concentrations of a PFI in PEDOT : PSS has detrimental effects on the device efficiency due to the low conductivity of the PFI. Using this approach, blue PHOLEDs with efficiencies of 9.4 lm W-1 (18.2 cdA(-1)) and 7.9 lm W-1 (20.4 cdA(-1)) at 100 cdm(-2) and 1000 cdm(-2), respectively, were demonstrated.

• 出版日期2014-5-21