The Role of Charge Balance and Excited State Levels on DevicePerformance of Exciplex-based Phosphorescent Organic Light EmittingDiodes

Collection with item attached
2017
Item details URL
http://open-repository.kisti.re.kr/cube/handle/open_repository/486089.do
DOI
10.1038/s41598-017-12059-2
Title
The Role of Charge Balance and Excited State Levels on DevicePerformance of Exciplex-based Phosphorescent Organic Light EmittingDiodes
Description
The authors would like thank Dr. Banglin Lee for materials design andsynthesis and Sangdong Kim, Dr. Ji Hwan Kim and Dr. Seung Yeon Kwak fordata collection and analysis. S.L. and H.K. specially thank SeokhwanHong for helping device fabrication and data analysis. Y.M.P. gratefullyacknowledges the financial support from the Korea Institute ofIndustrial Technology (KITECH), Republic of Korea, through the internalR&D program (Project No. EO170038).
abstract
The design of novel exciplex-forming co-host materials provides new opportunities to achieve high device performance of organic light emitting diodes (OLEDs), including high efficiency, low driving voltage and low efficiency roll-off. Here, we report a comprehensive study of exciplex-forming co-host system in OLEDs including the change of co-host materials, mixing composition of exciplex in the device to improve the performance. We investigate various exciplex systems using 5-(3-4,6-diphenyl1,3,5- triazin-2-yl) phenyl-3,9-diphenyl-9H-carbazole, 5-(3-4,6-diphenyl-1,3,5-triazin-2-yl) phenyl)9- phenyl-9H-3,9'-bicarbazole, and 2-(3-(6,9-diphenyl-9H-carbazol-4-yl) phenyl)-4-phenylbenzo[4,5] thieno[3,2-d] pyrimidine, as electron transporting (ET: electron acceptor) hosts and 9,9'-dipenyl-9H, 9' H-3,3'-bicarbazole and 9-([1,1'-biphenyl]-4-yl)-9'-phenyl-9H, 9' H-3,3'-bicarbazole as hole transporting (HT: electron donor) hosts. As a result, a very high current efficiency of 105.1 cd/A at 103 cd/m(2) and an extremely long device lifetime of 739 hrs (t(95): time after 5% decrease of luminance) are achieved which is one of the best performance in OLEDs. Systematic approach, controlling mixing ratio of HT to ET host materials is suggested to select the component of two host system using energy band matching and charge balance optimization method. Furthermore, our analysis on exciton stability also reveal that lifetime of OLEDs have close relationship with two parameters; singlet energy level difference of HT and ET host and difference of singlet and triplet energy level in exciplex.
provenance
Made available in Cube on 2018-09-28T15:58:15Z (GMT). No. of bitstreams: 0
language
English
author
Lee, Sangyeob
Koo, Hyun
Kwon, Ohyun
Park, Young Jae
Choi, Hyeonho
Lee, Kwan
Ahn, Byungmin
Park, Young Min
orcid
LEE, KWAN/0000-0002-8269-6579; Lee, Sangyeob/0000-0002-9957-990X
accessioned
2018-09-28T15:58:15Z
available
2018-09-28T15:58:15Z
issued
2017
citation
SCIENTIFIC REPORTS(7)
issn
2045-2322
uri
http://open-repository.kisti.re.kr/cube/handle/open_repository/486089.do
Funder
과학기술정보통신부
Funding Program
한국생산기술연구원연구운영비지원
Project ID
1711063090
Jurisdiction
Rep.of Korea
Project Name
VR기기 실감영상 구현을 위한 초고해상도 디스플레이 화소 제조기술 개발(1/3)
rights
openAccess
type
article


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