New Materials Hold Promise for More Efficient Flat-Panel Displays

PRINCETON, N.J. Feb. 23 -- Scientists at Princeton University have reported the creation of a number of light-emitting materials that could greatly accelerate the development of flat-panel computer screens and other compact video displays. The researchers experimented with the use of different materials in organic light-emitting diodes, or LEDs, which are thin films of molecules that can be induced to emit light. Organic LEDs are brighter, use less electricity, offer potentially truer colors and allow smaller pixel size than traditional liquid crystal displays.
Organic LEDs are typically made from two types of molecules, fluorescent and phosphorescent; to date, choosing between the two has involved a tradeoff. Fluorescence offers more variety, as scientists have identified more fluorescent molecules with suitable properties, such as good color quality and operational lifetime. Phosphorescent molecules are more efficient in terms of energy consumption, thanks to a discovery published by the same team in 1998.
The Princeton team found that by adding small quantities of energy-efficient phosphorescent molecules to fluorescent materials, they could create final products that emitted fluorescent light in a highly efficient manner. Researchers expect these findings to give developers of organic LEDs the best of both materials.