物理化学学报 >> 2012, Vol. 28 >> Issue (06): 1497-1501.doi: 10.3866/PKU.WHXB201203273

光化学和辐射化学 上一篇    下一篇

利用Cs基衍生物作为n型掺杂剂改善蓝色有机发光二极管的效率

申利莹1, 吴晓明1, 华玉林1, 董木森1, 印寿根1, 郑加金2   

  1. 1. 天津理工大学材料科学与工程学院, 显示材料与光电器件教育部重点实验室, 光电材料与器件天津市重点实验室, 天津 300384;
    2. 南京邮电大学光电工程学院, 南京 210003
  • 收稿日期:2011-12-28 修回日期:2012-03-27 发布日期:2012-05-17
  • 通讯作者: 吴晓明 E-mail:wxm@mail.nankai.edu.cn
  • 基金资助:

    国家自然科学基金(60906022, 60676051), 天津市自然科学基金(10JCYBJC01100), 天津市教委科学发展基金(2011ZD02)和江苏省高校自然科学发展基金(09KJB140006)资助项目

Improving the Efficiency of Blue Organic Light-Emitting Diodes by Employing Cs-Derivatives as the n-Dopant

SHEN Li-Ying1, WU Xiao-Ming1, HUA Yu-Lin1, DONG Mu-Sen1, YIN Shou-Gen1, ZHENG Jia-Jin2   

  1. 1. Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin Key Laboratory of Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, P. R. China;
    2. College of Optoelectronics Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210003, P. R. China
  • Received:2011-12-28 Revised:2012-03-27 Published:2012-05-17
  • Contact: WU Xiao-Ming E-mail:wxm@mail.nankai.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (60906022, 60676051), Natural Science Foundation of Tianjin, China (10JCYBJC01100), Scientific Developing Foundation of Tianjin Education Commission, China (2011ZD02), and Jiangsu Natural Science Development Foundation for University, China (09KJB140006).

摘要: 利用两种Cs基衍生物碳酸铯(Cs2CO3)和醋酸铯(CH3COOCs)作为n 型掺杂剂掺入到一种新型的电子传输材料2,9-二(2-萘基)-4,7-二苯基-1,10-菲啰啉(NBPhen)中来提高有机发光二极管(OLEDs)的效率. 实验结果表明: 器件的驱动电压明显降低, 并且优化后得到的Cs基n型掺杂器件(ITO/β-NPB/CBP:5%(w)N-BDAVBi/NBPhen/NBPhen:Cs2CO3 (or CH3COOCs)/Al)呈现出较好的电致发光性能, 在14 V时电流密度分别为551.80和527.88 mA·cm-2, 对应的亮度分别达到39750和39820 cd·m-2, 电流效率在亮度为10000 cd·m-2时分别为14.60 cd·A-1 (Cs2CO3掺杂)和14.40 cd·A-1 (CH3COOCs掺杂), 这些参数明显优于传统器件的发光性能(ITO/β-NPB/CBP:5%(w)N-BDAVBi/NBPhen/Cs2CO3/Al, 其在14 V时电流密度为312.39 mA·cm-2, 对应的亮度为25190 cd·m-2; 电流效率在亮度为10000 cd·m-2时为9.45 cd·A-1. 此外, 基于有机半导体掺杂原理和器件的能级结构对n型掺杂器件效率提高的原因进行了分析.

关键词: 有机发光二极管, 碳酸铯, 醋酸铯, n型电子传输层, 电致发光性能

Abstract: The efficiency of organic light-emitting diodes (OLEDs) was markedly improved using the novel electron transporting material 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBPhen) doped with Cs-derivatives including cesium carbonate (Cs2CO3) and cesium acetate (CH3COOCs) as the n-type dopant. The operating voltage of devices containing these materials as an n-type electron transporting layer (n-ETL) was significantly reduced. Optimized devices with Cs2CO3-doped or CH3COOCsdoped n-ETL (ITO/β-NPB/CBP:5%(w) N-BDAVBi/NBPhen/NBPhen:Cs2CO3 (or CH3COOCs)/Al) exhibited excellent electroluminescent performance with current densities of 551.80 and 527.88 mA·cm-2 at 14 V, corresponding brightnesses of 39750 and 39820 cd·m-2, and current efficiencies of 14.60 and 14.40 cd· A-1 at 10000 cd·m-2, respectively. These results were superior to that of conventional device (ITO/β-NPB/ CBP:5%(w)N-BDAVBi/NBPhen/Cs2CO3/Al) without an n-ETL, which exhibited a current density of 312.39 mA·cm-2 at 14 V, corresponding brightness of 25190 cd·m-2, and current efficiency of 9.45 cd·A-1 at 10000 cd·m-2. In addition, the reason for the increase in the efficiency of n-type doped devices has been analyzed based on the concept of the doping mechanism in organic semiconductors and the energy level scheme of the devices.

Key words: Organic light-emitting diodes, Cs2CO3, CH3COOCs, n-Type electron transporting layer, Electroluminescent performance

MSC2000: 

  • O644