铽配合物Tb(o-MBA)_3phen与PVK掺杂体系的发光机理  

Emission Mechanism in the Tb Complex Doped PVK System

作　　者：李秀芳[1] 邓振波[1] 张元元[1] 时玉萌[1] 王瑞芬[2] 

机构地区：[1]北京交通大学光电子技术研究所 [2]河北师范大学化学系,河北石家庄050091

出　　处：《发光学报》2007年第1期39-43,共5页Chinese Journal of Luminescence

基　　金：国家自然科学基金(90201004);北京市科委基金(H030430020410);河北省自然科学基金(203148)资助项目

摘　　要：合成了一种新型的稀土铽配合物材料Tb(o-MBA)3phen,并把它作为发光材料应用于有机电致发光器件中。将铽配合物与PVK的混合溶液用旋涂法制得发光层,并利用Alq3作为电子传输层制备了多种结构的电致发光器件:器件A:ITO/PVK∶Tb(o-MBA)3phen/LiF/Al;器件B:ITO/PVK∶Tb(o-MBA)3phen/BCP/Alq3/LiF/Al;器件C:ITO/BCP/PVK∶Tb(o-MBA)3phen/Alq3/LiF/Al。由器件A和C得到了纯正的、明亮的Tb3+的绿光发射,发射光谱中四个特征峰分别对应着能级5D4→7FJ(J=6,5,4,3)的跃迁,而PVK的发光完全被抑制。在光致发光中PVK的发射光谱和铽配合物的激发光谱有一定的重叠,两者之间可能存在Frster能量传递。同时PVK与铽配合物掺杂体系的激发光谱与纯PVK的激发光谱非常相像,而与铽配合物的激发光谱差别很大,这也说明掺杂体系中铽的发光有一部分来源于PVK分子的激发,PVK与铽配合物之间存能量传递过程。研究了掺杂体系的电致发光性能,在电致发光中,铽的发光主要来源于稀土配合物直接俘获载流子形成激子并复合发光。通过优化选择得到了发光性能较好的器件,器件的最大亮度在17V时达到180cd/m2。A new kind of rare earth （RE） complex Tb（o-MBA）3phen was synthesized, and was used as an emitting material in electroluminescence devices. The material was doped into poly N-vinylcarbazole （PVK） as the emitting layer, which is made by spin coating. Three kinds of devices were fabricated with the structures ： （A） ITO/PVK： Th （ o-MBA ） 3 Pherv/LiF/A1; （ B ） ITO/PVK： Tb （ o-MBA ） 3 phen/BCP/Alq3/IAF/A1, （C） ITO/BCP/PVK： rib （o-MBA） 3 phen/Alq3/LiWA1- Bright green emission could be obtained from Device A and Device C. Photoluminescence （PL） and electroluminescence （EL） mechanisms of this material were investi-gated. There is an overlap between the PL spectrum of PVK and the excitation spectrum of the terbium complex, so there should be Ftirster energy transfer process between them. The excitation spectrum of Tb（o-MBA） 3 phen doped PVK System is alike with the excitation spectrum of PVK, yet it is different with that of Tb（o-MBA）3phen. So the emission of Tb（o-MBA）3phen should partly come from the excitation of PVK. While in the OLED based on Tb（o-MBA） 3phen, the emission mainly come from the direct recombination of electron and hole. Bright green emission was obtained from the optimized multi-layer Device C and the highest EL brightness reached 180 cd/m^2 at the voltage of 17 V.

关 键 词：稀土配合物 电致发光 激子 

分 类 号：TN383.1[电子电信—物理电子学] TN873.3