|학술대회||2004년 가을 (10/08 ~ 10/09, 경북대학교)|
|권호||29권 2호, p.414|
|제목||Synthesis and Photophysical Property of Novel Electroluminescent Tris-Cyclometalated Ir(III) Dendrimers with Site Isolation Effect|
|초록||Phosphorescent materials for organic light-emitting diodes (OLEDs) have attracted substantial attention due to their potential of achieving a maximum internal quantum efficiency of 100% as well as higher environmental stability and rigidity, high brightness, and ease of sublimation etc. Iridium(III) complexes are known to exhibit high triplet quantum yield due to the spin-orbit coupling between the singlet and triplet states, which will enhance the triplet state and lead to high phosphorescence efficiencies. On the other hand, phosphorescent materials have some intrinsic disadvantages, such as the triplet-triplet annihilation and concentration quenching, caused by strong bimolecular interactions at high doping level. So it is very important to design and synthesize new materials to overcome these problems. Here, we have designed and synthesized several iridium(III) complexes based on 2-phenylpyridine dendrons with site isolation effect (그림. 1 & 2.). The PL intensity of Ir(III)PPYOG2 is almost 4 folds of that of Ir(III)PPYOMe. These results indicate that these complexes with the dendron-substituted ligands can overcome effectively the problems of iridium complexes such as the triplet-triplet annihilation and concentration quenching at high doping level. All the iridium(III) complexes have been characterized by NMR, FT-IR, Maldi-TOF and TGA, etc. In this presentation, their characterization and photophysical properties will be discussed in detail.
Fig. 1. PL spectra of Ir(III)PPYOMe, Ir(III)PPYOG1 and Ir(III)PPYOG2 in the thin film state at λex = 287 nm.
Fig. 2. PL spectra of Ir(III)PPYCH3, Ir(III)PPYCH2OG1 and Ir(III)PPYCH2OG2 in the thin film state at λex =287 nm.
|저자||노수균, 백남섭, 나민국, 김용희, 오재범, 이동훈, 강민수, 곽봉규, 김환규|
|키워드||Tris-Cyclometalated Ir(III) Complexes; Dendrimers; Site Isolation Effect; Organic Light-Emitting Diodes; Electroluminescent|