U n i v e r s i t y   o f   A r i z o n a   •  O l d   C h e m i s t r y  R o o m   1 0 8 b  •  5 2 0 / 6 2 6 - 3 3 8 7

Organic light-emitting diode (OLED) displays, working on the principle of electroluminescence, offer a number of advantages over established display technologies.  They are being heralded as the next-generation technology for advanced information display.  However, the current molecular and polymeric EL materials suffer from various imperfections, including the difficulty in achieving saturated monochromatic emission, inherently limited quantum efficiency, and strongly coupled processing and emission properties.  These issues must be addressed if the full technical, and ultimately, the market potentials of OLEDs are to be realized. 

One possible solution is to utilize photoluminescent (PL) lanthanide complexes as EL materials.  As compared with non-lanthanide materials, this class of emitters is believed to hold greater potential, due primarily to the f-electronic structure of the lanthanide elements and the unique energy-transfer mechanism of lanthanide-centered luminescence.  Extremely narrow and well-defined emissions have been realized, with the potential of achieving unlimited device quantum efficiency.  Furthermore, the processibility of the emissive lanthanide materials may be optimized without altering the metal-centered emission characteristics, since the ligand has little influence on the electronic structure of the lanthanide ion.  Stimulated by these propitious features, we are presently developing novel lanthanide-based OLED materials.  Our efforts have been concentrated on the improving the charge-transporting capability of such materials in order to enhance the light-emission efficiency.  We have produced a record-setting Tb(III)-based green-emitting device, which was recently highlighted in Chemical and Engineering News (J. Am. Chem. Soc. 2001, 123, 6179; C&EN 2001, 23 (July 2, 2001).