Electrophosphorescent organic light-emitting diodes with modified hole blocking layer

  • Shin, Y.C. (School of electrical engineering and computer science, Seoul National University) ;
  • Baek, H.I. (School of electrical engineering and computer science, Seoul National University) ;
  • Lee, C.H. (School of electrical engineering and computer science, Seoul National University)
  • Published : 2006.08.22

Abstract

The electrical and optical properties of electrophosphorescent organic light-emitting diodes (OLEDs) with modified hole blocking layer (HBL) were investigated. Well-known 2,9-dimethyl-4,7- diphenyl-1,10-phenanthroline (BCP) HBL is mixed with electrophosphorescent host material (4,4'-N,N'- dicarbazole-biphenyl: CBP) or electrophosphorescent dopant material (fac-tris(2-phenylpyridine) iridium: $Ir(ppy)_3$) or both. The highest external quantum efficiency was obtained in the device with $BCP-CBP-Ir(ppy)_3$ mixed HBL and we attribute this result to the additional charge recombination in mixed-HBL.

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