Until now, the aluminum tris (8-hydroxyquinoline) (Alq3) material - which is used as the emission and electron transport layer in organic light-emitting diodes - had to be deposited under high vacuum conditions, which requires costly equipment. Attaching it to a polymer backbone allows the material to be applied using solution processes - simple spin-coating methods already widely used for applying thin films of materials.
Beyond the implications for less costly and more flexible flat panel displays and similar devices, the new technique demonstrates that small molecules with interesting properties can be self-assembled onto standard polymer backbones. Using this "Lego-like" approach could have applications to other materials that are easier to process in polymeric form.
"This could have a significant impact for industry because it would make the manufacture of organic light-emitting diodes much easier," said Marcus Weck, an assistant professor in Georgia Tech's School of Chemistry and Biochemistry. "You can do this on a lab bench without million-dollar equipment. Being able to spin coat these organic systems could allow production of large surfaces suitable for displays."
Details of the work were presented March 27th at the 225th American Chemical Society National Meeting in New Orleans, LA. Sponsored by the National Science Foundation and the Office of Naval Research, the research has also been published in the journal Macromolecules.
Because they are based on polymers, organic light-emitting diodes produced with the new technique could offer another significant advantage - physical flexibility. That would allow production of displays that are less prone to damage and that can operate in shapes and forms not possible with current technology.