File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Host engineering for improving the performance of blue phosphorescent organic light-emitting devices

TitleHost engineering for improving the performance of blue phosphorescent organic light-emitting devices
Authors
KeywordsBlue
Organic light-emitting devices
Phosphorescence
Time-resolved phosphorescence decay
Triplet energy
Issue Date2011
PublisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/orgel
Citation
Organic Electronics: Physics, Materials, Applications, 2011, v. 12 n. 7, p. 1114-1119 How to Cite?
AbstractWe report an effective means to greatly improve the performance of blue phosphorescent organic light-emitting devices by doping well-known electron- or hole-transporting triplet host material, specifically, 3-(4-biphenyl)-4-phenyl- 5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ) or 4,4′,4′′- tris(N-carbazolyl)triphenylamine (TCTA), into emissive layer to form mixed host structures. A superior device performance with high current and power efficiencies of 47.4 cd/A and 37.3 lm/W, respectively, and more importantly, a theoretical maximum of external quantum efficiency of 21.9%, can be achieved for an optimized TCTA-doped device. On the other hand, doping of TAZ into hole-transporting host material would degrade device performance. It is found that, in addition to the well-known effects of charge carrier balance, both energy levels and triplet energies of mixed host materials play crucial roles in determining the device performance. As confirmed by the time-resolved phosphorescence decay studies, the lifetime of FIrpic is strongly dependent on the triplet energy of host materials and the shorter lifetime of triplet excitons with high Stern-Volmer quenching constant of 0.1564% -1 in TAZ-doped films is the origin of the low electroluminescence efficiency of the TAZ-doped devices. © 2011 Elsevier B.V. All rights reserved.
Persistent Identifierhttp://hdl.handle.net/10722/135035
ISSN
2015 Impact Factor: 3.471
2015 SCImago Journal Rankings: 1.215
ISI Accession Number ID
Funding AgencyGrant Number
Research Grants Council of the Hong Kong Special Administrative Region, ChinaHKU 700409P
University of Hong Kong
Funding Information:

The work described in this paper was fully supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. HKU 700409P). Infrastructural and facility support from the Strategic Research Theme on Molecular Materials, the University Development Fund of The University of Hong Kong, and the UGC Areas of Excellence Scheme (AoE/P-03/08), are also gratefully acknowledged. D.P.K. Tsang acknowledges the receipt of a postgraduate studentship and A.Y.Y. Tam a University Postdoctoral Fellowship, both from The University of Hong Kong.

References
Grants

 

DC FieldValueLanguage
dc.contributor.authorTsang, DPKen_HK
dc.contributor.authorChan, MYen_HK
dc.contributor.authorTam, AYYen_HK
dc.contributor.authorYam, VWWen_HK
dc.date.accessioned2011-07-27T01:26:22Z-
dc.date.available2011-07-27T01:26:22Z-
dc.date.issued2011en_HK
dc.identifier.citationOrganic Electronics: Physics, Materials, Applications, 2011, v. 12 n. 7, p. 1114-1119en_HK
dc.identifier.issn1566-1199en_HK
dc.identifier.urihttp://hdl.handle.net/10722/135035-
dc.description.abstractWe report an effective means to greatly improve the performance of blue phosphorescent organic light-emitting devices by doping well-known electron- or hole-transporting triplet host material, specifically, 3-(4-biphenyl)-4-phenyl- 5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ) or 4,4′,4′′- tris(N-carbazolyl)triphenylamine (TCTA), into emissive layer to form mixed host structures. A superior device performance with high current and power efficiencies of 47.4 cd/A and 37.3 lm/W, respectively, and more importantly, a theoretical maximum of external quantum efficiency of 21.9%, can be achieved for an optimized TCTA-doped device. On the other hand, doping of TAZ into hole-transporting host material would degrade device performance. It is found that, in addition to the well-known effects of charge carrier balance, both energy levels and triplet energies of mixed host materials play crucial roles in determining the device performance. As confirmed by the time-resolved phosphorescence decay studies, the lifetime of FIrpic is strongly dependent on the triplet energy of host materials and the shorter lifetime of triplet excitons with high Stern-Volmer quenching constant of 0.1564% -1 in TAZ-doped films is the origin of the low electroluminescence efficiency of the TAZ-doped devices. © 2011 Elsevier B.V. All rights reserved.en_HK
dc.languageengen_US
dc.publisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/orgelen_HK
dc.relation.ispartofOrganic Electronics: physics, materials, applicationsen_HK
dc.subjectBlueen_HK
dc.subjectOrganic light-emitting devicesen_HK
dc.subjectPhosphorescenceen_HK
dc.subjectTime-resolved phosphorescence decayen_HK
dc.subjectTriplet energyen_HK
dc.titleHost engineering for improving the performance of blue phosphorescent organic light-emitting devicesen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=1566-1199&volume=12&issue=7&spage=1114&epage=1119&date=2011&atitle=Host+engineering+for+improving+the+performance+of+blue+phosphorescent+organic+light-emitting+devices-
dc.identifier.emailChan, MY:chanmym@hku.hken_HK
dc.identifier.emailYam, VWW:wwyam@hku.hken_HK
dc.identifier.authorityChan, MY=rp00666en_HK
dc.identifier.authorityYam, VWW=rp00822en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1016/j.orgel.2011.03.046en_HK
dc.identifier.scopuseid_2-s2.0-79955519424en_HK
dc.identifier.hkuros186745en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-79955519424&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume12en_HK
dc.identifier.issue7en_HK
dc.identifier.spage1114en_HK
dc.identifier.epage1119en_HK
dc.identifier.eissn1878-5530-
dc.identifier.isiWOS:000291200400003-
dc.publisher.placeNetherlandsen_HK
dc.relation.projectPreparation and Characterization of Metal-doped Organic Thin Films for Tandem Organic Light Emitting Devices-
dc.identifier.scopusauthoridTsang, DPK=36605252900en_HK
dc.identifier.scopusauthoridChan, MY=7402597725en_HK
dc.identifier.scopusauthoridTam, AYY=16643873800en_HK
dc.identifier.scopusauthoridYam, VWW=18539304700en_HK
dc.identifier.citeulike9182179-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats