Performance Improvement of Organic Light Emitting Diodes Using Poly(N-vinylcarbazole) (PVK) as a Blocking Layer
High efficiency organic light‐emitting‐devices (OLED) have been fabricated by incorporation of a polymeric layer as a controller of the unbalanced charge. In device configuration of ITO/PEDOT:PSS/PVK/Alq3/LiF:Al, poly(N‐vinylcarbazole) (PVK) was selected as a block‐ing layer (BL) because it has a ho...
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Published in | Chinese journal of chemistry Vol. 28; no. 1; pp. 115 - 118 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
WILEY-VCH Verlag
01.01.2010
WILEY‐VCH Verlag Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | High efficiency organic light‐emitting‐devices (OLED) have been fabricated by incorporation of a polymeric layer as a controller of the unbalanced charge. In device configuration of ITO/PEDOT:PSS/PVK/Alq3/LiF:Al, poly(N‐vinylcarbazole) (PVK) was selected as a block‐ing layer (BL) because it has a hole transporting property and a higher band gap, especially a lower LUMO level than the emitting layer (Alq3) and a higher HOMO level than the hole injection layer (PEDOT: PSS). As a result, the optimal structure with this bl layer showed a peak efficiency of 6.89 cd/A and 2.30 lm/W compared to the device without the PVK layer of 1.08 cd/A, 0.27 lm/W. This result shows that the PVK layer could effec‐tively block the electrons from metal cathode and confine them in the emitting layer and accomplish the charge balance, which leads to enhanced hole‐electron balance for achieving high recombination efficiency. |
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Bibliography: | ArticleID:CJOC201090025 istex:514E83D2892BF9DBC0DC940491726271F32D009F ark:/67375/WNG-7M01HVB1-J Center for Nanostructured Materials Technology under 21st Frontier R&D Programs of the Ministry of Science and Technology, Korea - No. 2009K000463 the IT R&D program of MKE/KEIT - No. 2009-F-016-01, Development of Eco-Emotional OLED Flat-Panel Lighting |
ISSN: | 1001-604X 1614-7065 |
DOI: | 10.1002/cjoc.201090025 |