Doping effect of blue light-emitting electron transport molecule in blue organic light-emitting devices

被引：0

作者：

Kim, Youngkyoo ^{[1
]}

Moon, Byoungseok ^{[2
]}

Ha, Chang-Sik ^{[3
]}

机构：

[1] Experimental Solid State Physics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom

[2] Institute for Advanced Engineering, Yongin P.O. Box 25, Kyounggi-Do 449-860, Korea, Republic of

[3] Nano Information Materials Laboratory, Department of Polymer Science and Engineering, Pusan National University, Pusan 609-735, Korea, Republic of

来源：

Journal of Applied Physics | 2006年 / 100卷 / 06期

关键词：

Here we report the doping effect of blue light-emitting electron transport molecules on the performance of blue organic light-emitting devices (OLEDs). 4,4′-N,N′-dicarbazole-biphenyl (CBP) was chosen as a blue emission material (layer) for two main reasons: its wide band gap makes it suitable for blue emission; and its shifted energy band structure allows for easy electron injection. However; the main drawback of CBP is the low electron mobility and the large hole injection barrier. In order to overcome these weak points; the CBP nanolayer (50 nm thick) in blue OLEDs has been doped with 2-(2-hydroxyphenylbenzoxazole) lithium (LiPBO); which is known to be a blue light-emitting electron transport material. The result showed that the device performance (charge injection voltage; turn-on voltage; and current efficiency) was improved by doping the LiPBO molecule; an improvement that can be attributed to the enhanced electron mobility and the reduced hole injection barrier of the LiPBO-doped CBP nanolayer. However; the blue color purity of OLEDs marginally deteriorated as a result of the LiPBO doping. The worst Commission Internationale de l'Eclairage (CIE) color coordinate of OLEDs was x=0.16 and y=0.18 at 16 V; while the standard coordinates are x=0.14 and y=0.08; which is possibly due to the formation of exciplexes in a nanoscale. © 2006 American Institute of Physics;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Journal article (JA)

引用