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 July 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 July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
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:
from the past week

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