有机小分子电致磷光及发光机理研究进展

在过去10余年对小分子和聚合物电致发光器件的研究中,由于器件三线态激子能量没有得到充分的利用,使器件的内量子效率存在25%的理论极限,大大限制了其发光效率。为突破这一理论极限,在小分子主体材料中掺杂磷光染料制成电致磷光器件是近几年研究的热点,磷光染料的掺杂可以充分利用单线态和三线态激子,理论上器件的内量子效率可以达到100%。本文针对有机小分子电致磷光器件的发展、发光机理以及主客体分子间的能量传递等方面作了简明的讨论,指出了在器件设计时应该注意的一些问题。

The reseach development on organic small molecule electrophosphorescent device and light emitting mechanism

The lower usability of triplet exciton state energy always existed in the study of small molecule and polymer OLEDs in past years. The 25% theoretical limit of the internal quantum efficienc y bothered the researchers as usual. Recently, electrophosphorescent devices bas ed on small molecule have become a novel and attractive area of research. 100% i nternal quantum efficiency is possible to be reached theoretically for effective utilization of both singlet and triplet exciton states in these devices. In thi s paper, the development of organic small molecule electrophosphorescent device and the light emitting mechanism are briefly introduced. The energy transfer bet ween the host and the guest will be demonstrated thoroughly. Some problems in de vice designing will be pointed out. The future of the OLEDs will be looked forwa rd at the end of this paper.