Featured Research

from universities, journals, and other organizations

Unusual Electronic Properties In Bismuth-based Crystalline Material May Lead To Better Computer Chips And Solar Cells

Date:
February 20, 2009
Source:
Rutgers University
Summary:
Physicists have discovered unusual electronic properties in a material that has potential to improve solar cell efficiency and computer chip design. The material has potential to improve solar cell efficiency and computer chip design. Researchers determined that a crystal made of bismuth, iron and oxygen can act as a reversible diode, and that diodes made from this material generate current when light falls on them. The material appears sensitive to light at the blue end of the spectrum, a property that could increase solar cell efficiency.

Physicists at Rutgers University have discovered unusual electronic properties in a material that has potential to improve solar cell efficiency and computer chip design.

The scientists determined that a crystal made of bismuth, iron and oxygen can perform an electronic feat typically not feasible with conventional semiconductors. It acts as a reversible diode – essentially an electronic turnstile that lets current flow in one direction under certain conditions and in the opposite direction under different conditions. Traditional semiconductor diodes are not reversible – the direction of current flow that they allow is fixed during fabrication.

The researchers reported their findings February 18 in a paper published in Science Express, an advance web posting of papers to be published in upcoming issues of the journal Science.

The scientists also discovered that diodes made from this material generate current when light falls on them, making the material a potential candidate for future solar cells. The material appears very sensitive to light at the blue end of the spectrum, a property that has the potential to increase solar cell efficiency.

"We've reached the upper limit of efficiency with today's solar cells," said Sang-Wook Cheong, physics professor in the School of Arts and Sciences and one of the paper's five authors. "While we still don't know how efficiently this material will ultimately perform as a solar cell, we do need to keep investigating alternate technologies that show potential for improvement."

The crystal that Cheong and his colleagues investigated is a ferroelectric material, meaning that the crystal exhibits electrical polarization, or alignment. This polarization, which the scientists believe controls the crystal's ability to act as a diode, is known as a "bulk effect" – a characteristic that permeates the whole crystal. In contrast, traditional semiconductors act as diodes based on electrical effects at the interfaces between two different materials.

By applying an external voltage on the ferroelectric crystal, the polarization of the material reverses, along with the direction that the diode allows electricity to flow.

"This could make computer chip designs more flexible," said Cheong. "Engineers could design a single circuit element that performs one task under a certain configuration and another task under a different configuration."

The material belongs to class of crystalline materials known as perovskites, which have two positive ions of very different atomic sizes (in this case, bismuth and iron) bound to negative ions (in this case, oxygen). It has three oxygen atoms for each bismuth and iron atom.

Co-authors of the Science paper are Rutgers postdoctoral research fellow Taekjib Choi, graduate student Young Jai Choi, and associate professor Valery Kiryukhin. Another co-author, SeongSu Lee, was a Rutgers postdoctoral research fellow and is now at the Korea Atomic Energy Research Institute.

The National Science Foundation funded the research. Taekjib Choi was partially supported by a Korea Research Foundation Grant funded by the Korean government.


Story Source:

The above story is based on materials provided by Rutgers University. Note: Materials may be edited for content and length.


Cite This Page:

Rutgers University. "Unusual Electronic Properties In Bismuth-based Crystalline Material May Lead To Better Computer Chips And Solar Cells." ScienceDaily. ScienceDaily, 20 February 2009. <www.sciencedaily.com/releases/2009/02/090219141530.htm>.
Rutgers University. (2009, February 20). Unusual Electronic Properties In Bismuth-based Crystalline Material May Lead To Better Computer Chips And Solar Cells. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2009/02/090219141530.htm
Rutgers University. "Unusual Electronic Properties In Bismuth-based Crystalline Material May Lead To Better Computer Chips And Solar Cells." ScienceDaily. www.sciencedaily.com/releases/2009/02/090219141530.htm (accessed October 23, 2014).

Share This



More Matter & Energy News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

3D Printed Instruments Make Sweet Music in Sweden

3D Printed Instruments Make Sweet Music in Sweden

Reuters - Innovations Video Online (Oct. 23, 2014) — Students from Lund University's Malmo Academy of Music are believed to be the world's first band to all use 3D printed instruments. The guitar, bass guitar, keyboard and drums were built by Olaf Diegel, professor of product development, who says 3D printing allows musicians to design an instrument to their exact specifications. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins