Featured Research

from universities, journals, and other organizations

Switchable Two-color Light Source On A Silicon Chip

Date:
May 28, 2007
Source:
Forschungszentrum Dresden Rossendorf
Summary:
Silicon is the most important material for electronic chips and processors. Yet it has a big drawback: it is considered an indirect semiconductor -- it hardly emits any light. Therefore worldwide efforts in the labs of the microelectronics industry are aimed towards developing more efficient light sources based on silicon. Physicists have now managed to make silicon shine red and blue in an alternating fashion. This two-color light source could help to produce cheap and compact biosensors.

Photographs of the multi-color light emitter, 200 micrometer in diameter, taken under a microscope: the electrical current was 0.02 mA (a), 1 mA (b) and 2.5 mA (c), respectively. The violet color in (c) is a result of mixing the red and the blue.
Credit: Image courtesy of Forschungszentrum Dresden Rossendorf

Silicon is the most important material for electronic chips and processors. Yet it has a big drawback: being a so-called indirect semiconductor, it hardly emits any light. Therefore worldwide efforts in the labs of the microelectronics industry are aimed towards developing more efficient light sources based on silicon. Physicists at the Forschungszentrum Dresden-Rossendorf (FZD) now managed to make silicon shine red and blue in an alternating fashion. This two-color light source could help to produce cheap and compact biosensors. Recently a patent was filed related to this discovery.

It is not an easy task to make silicon shine, or, more accurately, to generate electroluminescence from this material, since in its usual form it can only emit with a very low efficiency. The Forschungszentrum Dresden-Rossendorf has worked successfully for several years on the realization of silicon based light emitters. Initially the physicists made a blue-violet emitter, which was then the basis of a silicon based optocoupler.

In 2004 they demonstrated ultraviolet, and then green light emitters. Now the physicists can switch the characteristics of the emitted light between two colors – red and blue – at will, depending only on the electrical current flowing through the device. The compatibility of these emitters with standard Silicon microelectronic technology is crucial, since the two-color nano-switch could easily integrated into common silicon chips.

For the fabrication of the test devices the group around Dr. Wolfgang Skorupa deposits an only 100 nanometer (one nanometer is one millionth of a millimeter) thin insulating silicon dioxide layer on the surface of the silicon wafer. Then the element Europium, which belongs to the group of rare-earth elements, is implanted using a beam of fast, charged atoms (ion beam). The peculiarity of Europium lies in the fact that it forms two different types of impurities carrying a different charge (oxidation state). These are the origin of the red and blue luminescence. Depending on the strength of the electrical current one or the other impurity type is excited to emit photons.

Possible applications of this two-color device lie in the area of biosensing. For example, the new silicon based light source could be used in the fast and cost-effective point-of-care analysis in health and environmental protection.

Reference: S. Prucnal, W. Skorupa, J. M. Sun, M. Helm, "Switchable two-color electroluminescence based on a Si metal-oxide-semiconductor structure doped with Eu“, in: Applied Physics Letters 90, 181121 (2007).


Story Source:

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


Cite This Page:

Forschungszentrum Dresden Rossendorf. "Switchable Two-color Light Source On A Silicon Chip." ScienceDaily. ScienceDaily, 28 May 2007. <www.sciencedaily.com/releases/2007/05/070527194838.htm>.
Forschungszentrum Dresden Rossendorf. (2007, May 28). Switchable Two-color Light Source On A Silicon Chip. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2007/05/070527194838.htm
Forschungszentrum Dresden Rossendorf. "Switchable Two-color Light Source On A Silicon Chip." ScienceDaily. www.sciencedaily.com/releases/2007/05/070527194838.htm (accessed July 28, 2014).

Share This




More Matter & Energy News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Carbon Trap: US Exports Global Warming

The Carbon Trap: US Exports Global Warming

AP (July 28, 2014) AP Investigation: As the Obama administration weans the country off dirty fuels, energy companies are ramping-up overseas coal exports at a heavy price. (July 28) Video provided by AP
Powered by NewsLook.com
Shipping Crates Get New 'lease' On Life

Shipping Crates Get New 'lease' On Life

Reuters - Business Video Online (July 25, 2014) Shipping containers have been piling up as America imports more than it exports. Some university students in Washington D.C. are set to get a first-hand lesson in recycling. Their housing is being built using refashioned shipping containers. Lily Jamali reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) 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:
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