Study of triplet exciton's energy transfer in white phosphorescent organic light-emitting diodes with multi-doped single emissive layer

Jin Wook Kim, Nam Ho Kim, Ju An Yoon, Seung Il Yoo, Jin Sung Kang, Kok Wai CHEAH, Fu Rong ZHU, Woo Young Kim*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

The performance of three color single emissive layer white phosphorescent organic light-emitting diodes (PHOLEDs), with different hole transporting materials of N,N′-diphenyl-N,N′-bis(l-naphthyl-phenyl)-(l,l′-biphenyl)-4,4′-diamine (NPB), 4,4-,4-tris-N-carbazolyl-tri-Phenylamine (TCTA) and 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), was analyzed. It is found that the luminous efficiency of white PHOLEDs is closely related to the triplet exciton energy level in the hole transporting layer (HTL). White PHOLEDs with a TAPC as HTL, having the highest triplet exciton energy level amongst the three different hole transporting materials, yielded external quantum efficiency of 25.5% at 4.5 V and a high luminous efficiency of 51 cd/A at 4.5 V with CIE color coordinates of (0.34, 0.39) at 10 V. The results reveal that the effective confinement of triplet excitons in white PHOLEDs with a high triplet exciton energy level HTL (TAPC) allows improving the luminous efficiency, as compared to the devices made with NPB and TCTA. Additionally, we demonstrated possibility for the loss of intensity in EL spectra of the white PHOLED devices with NPB and TCTA as HTL compared to that of the device with TAPC as HTL.

Original languageEnglish
Pages (from-to)57-62
Number of pages6
JournalOptical Materials
Volume40
DOIs
Publication statusPublished - 1 Feb 2015

Scopus Subject Areas

  • Electronic, Optical and Magnetic Materials
  • Computer Science(all)
  • Atomic and Molecular Physics, and Optics
  • Spectroscopy
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry
  • Electrical and Electronic Engineering

User-Defined Keywords

  • Hole transporting layer
  • NPB
  • Single emissive layer
  • TAPC
  • TCTA
  • White PHOLED

Fingerprint

Dive into the research topics of 'Study of triplet exciton's energy transfer in white phosphorescent organic light-emitting diodes with multi-doped single emissive layer'. Together they form a unique fingerprint.

Cite this