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08:54
Bimolecular Fluorescence Complementation
Published on: April 15, 2011
Divalent osmium complexes: synthesis, characterization, strong red phosphorescence, and electrophosphorescence.
Brenden Carlson1, Gregory D Phelan, Werner Kaminsky
1Departments of Chemistry and Materials Science and Engineering, University of Washington, Seattle, WA 98195, USA.
Journal of the American Chemical Society
|November 21, 2002
Summary
New divalent osmium complexes exhibit strong red phosphorescence and electrophosphorescence, achieving high quantum efficiency. These novel materials were successfully integrated into red organic light-emitting diodes (OLEDs) with impressive brightness and pure red emission.
Area of Science:
- Materials Science
- Inorganic Chemistry
- Photochemistry
Background:
- Metal-to-ligand-charge-transfer (MLCT) complexes are crucial for optoelectronic applications.
- Developing efficient red-emitting phosphorescent materials remains a significant challenge.
Purpose of the Study:
- To synthesize and characterize novel divalent osmium complexes with strong red phosphorescence.
- To investigate the potential of these complexes in fabricating red organic light-emitting diodes (OLEDs).
Main Methods:
- Synthesis of new polypyridyl ligands and their coordination with osmium(II).
- Characterization of photophysical properties, including phosphorescence emission and quantum efficiency.
- Fabrication and testing of double-layer OLED devices using the synthesized osmium complexes.
Main Results:
- Osmium complexes displayed strong MLCT absorption and red phosphorescent emission (611-651 nm) with up to 45% quantum efficiency.
- Fabricated OLEDs achieved brightness over 1400 cd/m(2) with a turn-on voltage of 8 V.
- The devices exhibited pure red emission with CIE coordinates (0.65, 0.34) and a maximum external quantum efficiency of 0.64%.
Conclusions:
- The novel divalent osmium complexes are highly efficient red phosphorescent emitters.
- These complexes show great promise for applications in red OLED technology.
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