Featured Research

from universities, journals, and other organizations

Light from silicon nanocrystal LEDs: Scientists develop multicolor LEDs without heavy metals

Date:
February 22, 2013
Source:
Karlsruhe Institute of Technology
Summary:
Silicon nanocrystals have a size of a few nanometers and possess a high luminous potential. Scientists have now succeeded in manufacturing silicon-based light-emitting diodes (SiLEDs). They are free of heavy metals and can emit light in various colors.

Liquid-processed SiLEDs: By changing the size of the silicon nanocrystals, color of the light emitted can be varied.
Credit: F. Maier-Flaig, KIT/LTI

Silicon nanocrystals have a size of a few nanometers and possess a high luminous potential. Scientists of KIT and the University of Toronto/Canada have now succeeded in manufacturing silicon-based light-emitting diodes (SiLEDs). They are free of heavy metals and can emit light in various colors.

The team of chemists, materials researchers, nanoscientists, and opto-electronic experts presents its development in the journal Nano Letters.
 
Silicon dominates in microelectronics and photovoltaics industry, but has been considered unsuitable for light-emitting diodes for a long time. However, this is not true for nanoscopic dimensions: Minute silicon nanocrystals can produce light. These nanocrystals consist of a few hundred to thousand atoms and have a considerable potential as highly efficient light emitters, as was demonstrated by the team of Professor Uli Lemmer and Professor Annie K. Powell from KIT as well as Professor Geoffrey A. Ozin from the University of Toronto. In a joint project, the scientists have now succeeded in manufacturing highly efficient light-emitting diodes from the silicon nanocrystals.

So far, manufacture of silicon light-emitting diodes has been limited to the red visible spectral range and the near infrared. As regards the efficiency of silicon diodes emitting red light, researchers from Karlsruhe are already top in the world. “Controlled manufacture of diodes emitting multicolor light, however, is an absolutely novelty,” explains Florian Maier-Flaig, scientist of the Light Technology Institute (LTI) of KIT and doctoral student of the Karlsruhe School of Optics and Photonics (KSOP). KIT scientists specifically adjust the color of the light emitted by the diodes by separating nanoparticles depending on their size. “Moreover, our light-emitting diodes have a surprising long-term stability that has not been reached before,” Maier-Flaig reports. The increased service life of the components in operation is due to the use of nanoparticles of one size only. This enhances the stability of the sensitive thin-film components. Short circuits due to oversized particles are excluded.
 
The development made by the researchers from Karlsruhe and Toronto is also characterized by an impressing homogeneity of the luminous areas. The KIT researchers are among the few teams in the world that know how to manufacture such devices. “With the liquid-processed silicon LEDs that may potentially be produced on large areas as well as at low costs, the nanoparticle community enters new territory, the associated potentials of which can hardly be estimated today. But presumably, textbooks about semiconductor components have to be rewritten,” says Geoffrey A. Ozin, who is presently working as a KIT distinguished research fellow at KIT’s Center for Functional Nanostructures (CFN).
 
The SiLEDs also have the advantage that they do not contain any heavy metals. In contrast to cadmium selenide, cadmium sulfide or lead sulfide used by other groups of researchers, the silicon used by this group for the light-emitting nanoparticles is not toxic. Moreover, it is available at low costs and highly abundant on earth. Due to their many advantages, the SiLEDs will be developed further in cooperation with other partners.


Story Source:

The above story is based on materials provided by Karlsruhe Institute of Technology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Florian Maier-Flaig, Julia Rinck, Moritz Stephan, Tobias Bocksrocker, Michael Bruns, Christian Kübel, Annie K. Powell, Geoffrey A. Ozin, Uli Lemmer. Multicolor Silicon Light-Emitting Diodes (SiLEDs). Nano Letters, 2013; 13 (2): 475 DOI: 10.1021/nl3038689

Cite This Page:

Karlsruhe Institute of Technology. "Light from silicon nanocrystal LEDs: Scientists develop multicolor LEDs without heavy metals." ScienceDaily. ScienceDaily, 22 February 2013. <www.sciencedaily.com/releases/2013/02/130222075734.htm>.
Karlsruhe Institute of Technology. (2013, February 22). Light from silicon nanocrystal LEDs: Scientists develop multicolor LEDs without heavy metals. ScienceDaily. Retrieved August 2, 2014 from www.sciencedaily.com/releases/2013/02/130222075734.htm
Karlsruhe Institute of Technology. "Light from silicon nanocrystal LEDs: Scientists develop multicolor LEDs without heavy metals." ScienceDaily. www.sciencedaily.com/releases/2013/02/130222075734.htm (accessed August 2, 2014).

Share This




More Matter & Energy News

Saturday, August 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Tesla, Panasonic Ink Deal To Make Huge Battery 'Gigafactory'

Tesla, Panasonic Ink Deal To Make Huge Battery 'Gigafactory'

Newsy (July 31, 2014) — The deal will help build a massive battery factory that Tesla says will produce 500,000 lithium batteries by 2020. Video provided by Newsy
Powered by NewsLook.com
Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) — British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
7 Ways to Use Toothpaste: Howdini Hacks

7 Ways to Use Toothpaste: Howdini Hacks

Howdini (July 30, 2014) — Fresh breath and clean teeth are great, but have you ever thought, "my toothpaste could be doing more". Well, it can! Lots of things! Howdini has 7 new uses for this household staple. Video provided by Howdini
Powered by NewsLook.com
Smoked: 2015 Ducati Diavel Vs 2014 Chevy Corvette Stingray Drag Race

Smoked: 2015 Ducati Diavel Vs 2014 Chevy Corvette Stingray Drag Race

Cycle World (July 30, 2014) — The Bonnier Motorcycle Group presents Smoked; a three part video series. In this episode the 2015 Ducati Diavel takes on the 2014 Chevy Corvette Stingray Video provided by Cycle World
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