New multifunctional host and emitter materials containing carbazole as the building block for improved charge balance in blue OLEDs

ORGN 497

Asanga B Padmaperuma, asanga.padmaperuma@pnl.gov, Phillip K Koech, Harry Cai, Jonathan L Male, Linda S Sapochak, and Paul E Burrows. Department of Materials Chemistry and Surface Research, Pacific Northwest National Laboratory, 908 Battelle Blvd, MS K2-44, Richland, WA 99354
Organic light-emitting device (OLED) technology has advanced rapidly over the last decade with significant effort now focused on solid state lighting applications. Efficient blue OLEDs are a vital component of white lighting, but adequate materials for achieving charge balance necessary for high efficiency and stability are lacking. Conventional approaches to emitter material design have mainly focused on color tuning; however, multi-functional materials are needed to balance charge transport in the emissive layer. Recently, electron transporting host materials for blue phosphors with good thermal properties and favorable triplet energies have been achieved by substitution of small molecule building blocks with phosphine oxide moieties. In this presentation, we will show how inductive effects of phosphine oxide substitution are used to achieve both electron- and ambipolar- charge transport of carbazole. Effort towards achieving charge balance by development of both multi-functional blue emitters and high triplet energy host materials incorporating carbazole are described.
 

Materials, Devices and Switches
1:00 PM-4:40 PM, Wednesday, April 9, 2008 Morial Convention Center -- La Nouvelle, Blrm. C, Oral

Division of Organic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008