电压调制变色有机电致发光器件中的能量传递  

Energy Transfer in the Color-tunable Organic Electroluminescence by Voltage Modulation

作　　者：章婷[1] 徐征[1] 陈晓红[1] 苏艳梅[1] 刘育新[1] 沈鸿[1] 

机构地区：[1]北方交通大学光电子技术研究所信息存储,显示与材料部级开放实验室,北京100044

出　　处：《发光学报》2001年第4期347-350,共4页Chinese Journal of Luminescence

基　　金：国家自然科学基金资助项目(29992530;19974002);北方交通大学攀登基金资助项目

摘　　要：研究了不同掺杂浓度下 ＰＶＫ：Ｒｕｂｒｅｎｅ的光致发光及电致发光的特性。发现掺杂浓度较低的 ＰＶＫ：Ｒｕｂｒｅｎｅ的光致发光与电致发光有较大差别，这是Ｆｏｒｓｔｅｒ能量传递及电致发光中陷阱中的电子对空穴的吸引作用使得 ＰＶＫ激子在光致发光和电致发光中的复合速率不同造成的。同时各掺杂浓度在 ５ｗｔ％以下的ＰＶＫ：Ｒｕｂｒｅｎｅ发光随电压的增加呈现变色，这是能量传递不完全时，未参与能量传递的ＰＶＫ激子复合速率随电压升高增大的结果。There have been a large number of documents and patents on organic/polymer electrolumi- nescence devices, in addition a good many organic and polymer materials have been successfully synthesized since the first report of high performance double-layer organic light-emitting device(OLED) by C. W. Tang in 1987, and much progress has been made in this field. Study on the dye-doped organic light-emitting diodes is very significant. And a useful technique for altering the color of OLEDs involves the doping of a small amount of a fluorescent dye into one of the organic layers of an OLED. But little study on the color- tunable organic electroluminescence by the voltage applied at a doping level is reported. In this work, dye(Rubrene) was doped into poly( n-vinylcarbazole) (PVK) at different weight ratios and the characters of photoluminescence and electroluminscence were studied. The device structure of ITO/ PVK: Rubrene/Al was employed . The result shows that there are great difference between the photolumi- nescence and electroluminescence at a doping ratio of 2wt%. It is concluded that energy transfer in these dye-doped devices occurs by Forster energy transfer processes. And the trap effect of electrons of Rubrene on holes of PVK results in different combination probability of PVK exciton in photoluminescence and electroluminescence. The two cases result in the difference between the spectrum of photoluminescence and that of electroluminscence. At the same time, EL devices with Rubrene doped PVK as emission layer are color- tunable when the bias voltage was increased. It indicates that the energy transfer process from PVK to Rubrene is not complete. And the combination probability of PVK exciton which does not contribute to the emmision of Rubrene is increased when the bias voltage increases.

关 键 词：有机电致发光器件 电压调制变色 能量传递 聚乙烯基咔唑 PVK 染料掺杂 

分 类 号：TN383.1[电子电信—物理电子学]