Volume 89 Issue 46 | p. 35 | Concentrates
Issue Date: November 14, 2011

Turning Heat Into Electricity

Device converts infrared radiation directly into electricity
Department: Science & Technology
News Channels: Environmental SCENE, Materials SCENE
Keywords: infrared, plasmon, optics, energy conversion
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Each line on this slide is an energy-harvesting device that can convert infrared radiation into current.
Credit: Fuming Wang
Each line on this slide held between fingertips is an energy-harvesting device that can convert infrared radiation into current.
 
Each line on this slide is an energy-harvesting device that can convert infrared radiation into current.
Credit: Fuming Wang

A new thin-film device turns an annoying optical effect into a means to convert infrared radiation directly into electricity (Nano Lett., DOI: 10.1021/nl203196z). Researchers hope it will lead to inexpensive, flexible films that could recoup wasted energy when wrapped around hot machines. The hotter an object is, the more infrared radiation it produces. The device relies on waves called plasmons, which are created when photons strike a metal surface. Plasmons decay quickly and transfer their energy to electrons in the metal. Normally, this decay process is a nuisance for optics researchers. But Nicholas Melosh of Stanford University decided to harvest the resulting high-energy electrons with a simple device consisting of two thin-film metal electrodes sandwiching an insulating layer. After a plasmon decays in the top electrode, the resulting excited electrons jump across the insulating layer to the other electrode, generating a current. Although the device’s efficiency is now only 1%, Melosh thinks that it would need to reach only 4 to 5% efficiency to be practical.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society
Comments
Ben (Mon Nov 14 12:21:37 EST 2011)
Wasn't this story in last week's CEN?
Lila Guterman (Tue Nov 15 14:58:03 EST 2011)
Thanks for noticing! It appeared as news (in a longer version) in C&EN online but didn't appear till this week in print.

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