Energy News  





. Advance By Chemists May Lead To Better Displays On Laptop Computers And Cell Phones

The manner in which the polymer chains incorporate into the porous glass of the silica matrix helps to confine the light in the material, enhancing the lasing process by producing what is known as a "graded-index waveguide." In most lasers, confining the light is typically done with external mirrors.
by Staff Writers
Los Angeles CA (SPX) Sep 19, 2007
UCLA chemists working at the nanoscale have developed a new, inexpensive means of forcing luminescent polymers to give off polarized light and of confining that light to produce polymer-based lasers. The research, which could lead to a brighter polarized light source for LEDs in laptop computers, cell phones and other consumer electronics devices, currently appears in the advance online edition of the journal Nature Nanotechnology.

The research was conducted by UCLA professors of chemistry and California NanoSystems Institute members Sarah Tolbert and Benjamin J. Schwartz, and colleagues, including Hirokatsu Miyata, a research scientist with Canon's Nanocomposite Research division in Japan. The research is federally funded by the National Science Foundation and the Office of Naval Research and privately funded by Canon.

The researchers have succeeded in taking semiconducting polymers - plastics that consist of long chains of atoms that work as semiconductors - and stretching them out in a silica (glass) host matrix so that they have new optical properties.

"If you have polymer chains that can wiggle like spaghetti, it's hard to make them all point in the same direction," Tolbert said. "What we do is take tiny, nanometer-sized holes in a piece of glass and force the polymer chains into the holes. The holes are so small that the spaghetti chains have no space to coil up. They have to lie straight, and all the chains end up pointing in the same direction."

Because the chains point in the same direction, they absorb polarized light and give off polarized light. Lining up the polymer chains also provides advantages for laser technology, because all the chains can participate in the lasing process, and they can make the light polarized without the need for any external optical elements, Tolbert said.

As a postdoctoral fellow, Schwartz was one of the original discoverers in the 1990s that lasers could be made out of randomly oriented semiconducting polymer chains.

"Our new materials exploit the fact that the polymer chains are all lined up to make them into lasers that function very differently from lasers made out of random polymers," Schwartz said.

The manner in which the polymer chains incorporate into the porous glass of the silica matrix helps to confine the light in the material, enhancing the lasing process by producing what is known as a "graded-index waveguide." In most lasers, confining the light is typically done with external mirrors.

"Our materials don't need mirrors to function as lasers, because the material that's lasing is also serving to confine the light," Schwartz said.

In combination, the alignment of the polymer chains and the confinement of the light make it 20 times easier for the new materials to lase than if a randomly oriented polymer sample were used. And because polymers can be dissolved easily in solvents, they are inexpensive to process. The glass host matrix with the aligned nanoscale pores is also inexpensive to produce.

"Usually polarized and cheap don't go together," Tolbert said.

The research opens the possibility of additional applications for the new materials as a brighter polarized source for displays in products with LED-type displays, including cell phones, laptops and Palm Pilots.

"If you take an inexpensive light source with which you could excite the aligned polymer chains and get the chains to reemit, you potentially have a more efficient way to generate polarized light." Tolbert said. "This would allow displays to be brighter with less power consumption, and you could get longer battery life."

Tolbert has collaborated with Canon for years on the development of this class of new materials. In addition to Tolbert, Schwartz and Miyata, co-authors include UCLA researcher and former postdoctoral scholar Ignacio Martini, UCLA chemistry graduate student Ian Craig, and UCLA chemistry graduate student William Molenkamp.

Community
Email This Article
Comment On This Article

Related Links
University of California - Los Angeles
Powering The World in the 21st Century at Energy-Daily.com




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
Chad president to hold Darfur talks in China
N'Djamena (AFP) Sept 18, 2007
Chadian President Idriss Deby Itno is to discuss the Darfur conflict and sign oil and gas deals during a four-day visit to China starting Wednesday, Chadian officials said.

.
Get Our Free Newsletters Via Email
  



  • Chad president to hold Darfur talks in China
  • Analysis: Iraq, oil and Greenspan's Gospel
  • Advance By Chemists May Lead To Better Displays On Laptop Computers And Cell Phones
  • New Jersey's Largest Electrical Workers Union Joins Clean Reliable Energy Coalition

  • Areva official to visit China pending EPR contract
  • SAfrica out of GNEP to keep right to enrich uranium: minister
  • Indian Communists demand delay to US nuclear deal
  • Vietnam sends highly enriched uranium to Russia

  • Volcanoes Key To Earth's Oxygen Atmosphere
  • Invisible Gases Form Most Organic Haze In Both Urban And Rural Areas
  • BAE Systems Completes Major New Facility For Ionospheric Physics Research
  • NASA Satellite Captures First View Of Night-Shining Clouds

  • Refugia Of The Brazilian Atlantic Rainforest Could Be The Basis For Its Regeneration
  • Indonesia proposes rainforest nations climate group
  • ASEAN urged to muster political will to deal with forest fire haze
  • Humans Fostering Forest-Destroying Disease

  • HARDY Rice: Less Water, More Food
  • UD Leads 5 Million Dollar Research Project On Rice Epigenetics
  • EU proposes easing grain rules to help fight high prices
  • Transgenic Maize Is More Susceptible To Aphids

  • China to hold first-ever 'no car day' on Saturday
  • Judge hits auto makers, allows Vermont to limit emissions
  • EU automakers reject 2012 deadline for CO2 cuts
  • Greener cars - a brief guide to the new terms

  • Squabble over airline carbon emissions takes flight
  • Boeing Projects 340 Billion Dollar Market For New Airplanes In China
  • KC-30 Tanker's General Electric Power Plant Completes One Million Takeoff And Landing Cycles
  • NCAR Teams With United Airlines To Pinpoint Turbulence In Clouds: Research Can Help Reduce Delays, Injuries, Costs

  • Nuclear Power In Space - Part 2
  • Outside View: Nuclear future in space
  • Nuclear Power In Space
  • Could NASA Get To Pluto Faster? Space Expert Says Yes - By Thinking Nuclear

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement