Nanocrystal Discovery Has Solar Cell Potential - InformationWeek
IoT
IoT
News
News
1/9/2006
12:19 PM
50%
50%
RELATED EVENTS
Moving UEBA Beyond the Ground Floor
Sep 20, 2017
This webinar will provide the details you need about UEBA so you can make the decisions on how bes ...Read More>>

Nanocrystal Discovery Has Solar Cell Potential

Scientists at Los Alamos National Laboratory have discovered a process that increases the potential for using nanocrystals as solar cell materials for producing higher electrical outputs than current solar cells.

Scientists at Los Alamos National Laboratory have discovered a process that increases the potential for using nanocrystals as solar cell materials for producing higher electrical outputs than current solar cells.

The discovery, announced last week and published in the journals Nature Physics and Applied Physics Letters, sheds light on the mechanism for carrier multiplication, a phenomenon in which semiconductor nanocrystals respond to photons by producing multiple electrons. Scientists now believe that carrier multiplication can be applied to more materials than previously thought. The findings herald the possibility of new photovoltaic technologies that make use of traditional solar cell materials such as cadmium telluride.

According to Los Alamos, carrier multiplication isn't unique to lead selenide nanocrystals, but also occurs in nanocrystals of other compositions like cadmium selenide.

"Our research of carrier multiplication in previous years was really focused on analyzing the response of lead selenide nanocrystals to very short laser pulses," Los Alamos scientist Richard Schaller said in a prepared statement last week. "We discovered that absorption of a single photon could produce two or even three excited electrons. We knew, somewhat instinctively, that carrier multiplication was probably not confined to lead selenide, but we needed to pursue the question."

Scientists believe carrier multiplication occurs through instantaneous photoexcitation of multiple electrons and it relies on the unique physics of the nanoscale- size regime.

"Carrier multiplication actually relies upon very strong interactions between electrons squeezed within the tiny volume of a nanoscale semiconductor particle," lead project scientist Victor Klimov explained in a written statement. "That is why it is the particle size, not its composition that mostly determines the efficiency of the effect. In nanosize crystals, strong electron-electron interactions make a high-energy electron unstable. This electron only exists in its so-called 'virtual state' for an instant before rapidly transforming into a more stable state comprising two or more electrons."

Carrier multiplication could be used in solar-fuel technologies and specifically, the production of hydrogen by photo-catalytic water splitting, according to the team of Los Alamos researchers. The production of hydrogen by photo-catalytic water splitting requires four electrons per water molecule and its efficiency can be dramatically enhanced if multiple electrons can be produced through a single-photon absorption event.

Comment  | 
Print  | 
More Insights
Comments
Oldest First  |  Newest First  |  Threaded View
How Enterprises Are Attacking the IT Security Enterprise
How Enterprises Are Attacking the IT Security Enterprise
To learn more about what organizations are doing to tackle attacks and threats we surveyed a group of 300 IT and infosec professionals to find out what their biggest IT security challenges are and what they're doing to defend against today's threats. Download the report to see what they're saying.
Register for InformationWeek Newsletters
White Papers
Current Issue
IT Strategies to Conquer the Cloud
Chances are your organization is adopting cloud computing in one way or another -- or in multiple ways. Understanding the skills you need and how cloud affects IT operations and networking will help you adapt.
Video
Slideshows
Twitter Feed
Sponsored Live Streaming Video
Everything You've Been Told About Mobility Is Wrong
Attend this video symposium with Sean Wisdom, Global Director of Mobility Solutions, and learn about how you can harness powerful new products to mobilize your business potential.
Flash Poll