Low Energy White LEDs

  • Author: ChemistryViews
  • Published: 27 May 2011
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
  • Source / Publisher: Advanced Materials/Wiley-VCH
thumbnail image: Low Energy White LEDs

Light-emitting diodes (LEDs) that produce white light can be made by coating a blue LED with phosphor or by mixing differently colored LEDs, which requires electronic circuits to control the blending of the colors. Phosphor-based LEDs are less efficient and degrade faster than other LEDs.

Zhiyuan Xie, Lixiang Wang, and co-workers, Chinese Academy of Sciences, have developed a star-shaped polymer that could be used in white LEDs. They incorporate six polyfluorene arms around a donor-acceptor type core. The simultaneous blue emission from the arms and orange emission from the core resulted in white electroluminescence with the highest efficiency reported for a single-polymer white LED. Core aggregation, and subsequent quenching, was prevented by the branched arms which makes the new polymers more effective than previous linear and star-shaped single-polymers.

Polymer-based white LEDs could overcome the efficiency problems seen with other LEDs and lead to their use in flat-panel displays or as low energy light sources.

Image: (c) Wiley-VCH

Article Views: 2979

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission. more

Follow on Facebook Follow on Twitter Follow on YouTube Follow on LinkedIn Follow on Instagram RSS Sign up for newsletters

Magazine of Chemistry Europe (16 European Chemical Societies) published by Wiley-VCH