Journal
ADVANCED FUNCTIONAL MATERIALS
Volume 21, Issue 6, Pages 1168-1178Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/adfm.201002066
Keywords
-
Categories
Funding
- National Natural Science Foundation of China [90922020, 50773057]
- National Basic Research Program of China [2009CB623602, 2009CB930603]
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Fundamental Research Funds for the Central Universities of China
Ask authors/readers for more resources
A series of tetraarylsilane compounds, namely p-BISiTPA (1), m-BISiTPA (2), p-OXDSiTPA (3), m-OXDSiTPA (4), are designed and synthesized by incorporating electron-donating arylamine and electron-accepting benzimidazole or oxadiazole into one molecule via a silicon-bridge linkage mode. Their thermal, photophysical and electrochemical properties can be finely tuned through the different groups and linking topologies. The para-disposition compounds 1 and 3 display higher glass transition temperatures, slightly lower HOMO levels and triplet energies than their meta-disposition isomers 2 and 4, respectively. The silicon-interrupted conjugation of the electron-donating and electron-accepting segments gives these materials the following advantages: i) relative high triplet energies in the range of 2.69-2.73 eV; ii) HOMO/LUMO levels of the compounds mainly depend on the electron-donating and electron-accepting groups, respectively; iii) bipolar transporting feature as indicated by hole-only and electron-only devices. These advantages make these materials ideal universal hosts for multicolor phosphorescent OLEDs. 1 and 3 have been demonstrated as universal hosts for blue, green, orange and white electrophosphorescence, exhibiting high efficiencies and low efficiency roll-off. For example, the devices hosted by 1 achieve maximum external quantum efficiencies of 16.1% for blue, 22.7% for green, 20.5% for orange, and 19.1% for white electrophosphorescence. Furthermore, the external quantum efficiencies are still as high as 14.2% for blue, 22.4% for green, 18.9% for orange, and 17.4% for white electrophosphorescence at a high luminance of 1000 cd m(-2). The two-color, all-phosphor white device hosted by 3 acquires a maximum current efficiency of 51.4 cd A(-1), and a maximum power efficiency of 51.9 lm W-1. These values are among the highest for single emitting layer white PhOLEDs reported till now.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available