Featured Research

from universities, journals, and other organizations

Scientists Develop Novel Multi-color Light-emitting Diodes

Date:
May 18, 2005
Source:
Los Alamos National Laboratory
Summary:
A team of University of California scientists at Los Alamos National Laboratory have developed the first completely inorganic, multi-color light-emitting diodes (LEDs) based on colloidal quantum dots encapsulated in a gallium nitride (GaN) semiconductor. The work represents a new "hybrid" approach to the development of solid-state lighting. Solid-state lighting offers the advantages of reduced operating expenses, lower energy consumption and more reliable performance.

LOS ALAMOS, N.M., May 17, 2005 -- A team of University of California scientists at Los Alamos National Laboratory have developed the first completely inorganic, multi-color light-emitting diodes (LEDs) based on colloidal quantum dots encapsulated in a gallium nitride (GaN) semiconductor. The work represents a new "hybrid" approach to the development of solid-state lighting. Solid-state lighting offers the advantages of reduced operating expenses, lower energy consumption and more reliable performance.

Related Articles


In research published in the current issue of the scientific journal Nano Letters, the team reports on the first successful demonstration of electroluminescence from an all-inorganic, nanocrystal-based architecture where semiconductor nanocrystals are incorporated into a p-n junction formed from semiconducting GaN injection layers. The new LEDs utilize a novel type of color-selectable nanoemitters, colloidal quantum dots, and makes use of emerging GaN manufacturing technologies.

According to Klimov, who leads the nanocrystal-LED research effort, "numerous technologies could benefit from energy efficient, color-selectable solid-state lighting sources ranging from automotive and aircraft instrument displays to traffic signals and computer displays. Semiconductor nanocrystals, known also as quantum dots, are attractive nanoscale light emitters that combine size-controlled emission colors and high emission efficiencies with chemical flexibility and excellent photostability. The use of nanocrystals in light-emitting technologies has, however, always been hindered by the difficulty of making direct electrical connections to the nanocrystals. By putting the quantum dots between GaN injection layers, we've gotten around this difficulty."

The secret to making the electrical connection to the quantum dots is the use of a technique developed at Los Alamos by Mark Hoffbauer and his team that utilizes a beam of energetic, neutral nitrogen atoms for growing GaN films. The technique, called ENABLE (for Energetic Neutral Atom Beam Lithography/Epitaxy), allows for the low-temperature encapsulation of nanocrystals in semiconducting GaN without adversely affecting their luminescence properties. By encapsulating one nanocrystal layer or two layers of nanocrystals of different sizes, the researchers have demonstrated that their LEDs can emit light of either a single color or two different colors. The two color-operation regime is an important step toward creating devices that produce white light.

The development of the multicolor LEDs is the result of a collaboration between two Laboratory research groups: Klimov's quantum-dot team and Hoffbauer's team developing advanced nanoscale processing technologies. Laboratory researchers critical to the project's success also include Alexander Mueller, Melissa Petruska, Marc Achermann, Donald Werder, and Elshan Akhadov. Daniel Koleske of Sandia National Laboratories provided the GaN substrates used for the LED structures.

The Los Alamos Laboratory-Directed Research and Development (LDRD) program provided funding for the Los Alamos work as an Exploratory Research (ER) project. The research fits into a broader area of expertise that Los Alamos National Laboratory maintains in the field of nanotechnology in general, and quantum dot research in particular.


Story Source:

The above story is based on materials provided by Los Alamos National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Los Alamos National Laboratory. "Scientists Develop Novel Multi-color Light-emitting Diodes." ScienceDaily. ScienceDaily, 18 May 2005. <www.sciencedaily.com/releases/2005/05/050518200912.htm>.
Los Alamos National Laboratory. (2005, May 18). Scientists Develop Novel Multi-color Light-emitting Diodes. ScienceDaily. Retrieved January 25, 2015 from www.sciencedaily.com/releases/2005/05/050518200912.htm
Los Alamos National Laboratory. "Scientists Develop Novel Multi-color Light-emitting Diodes." ScienceDaily. www.sciencedaily.com/releases/2005/05/050518200912.htm (accessed January 25, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, January 25, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NTSB: Missing Planes' Black Boxes Should Transmit Wirelessly

NTSB: Missing Planes' Black Boxes Should Transmit Wirelessly

Newsy (Jan. 23, 2015) In light of high-profile plane disappearances in the past year, the NTSB has called for changes to make finding missing aircraft easier. Video provided by Newsy
Powered by NewsLook.com
Iconic Metal Toy Meccano Goes Robotic

Iconic Metal Toy Meccano Goes Robotic

Reuters - Innovations Video Online (Jan. 22, 2015) Classic children&apos;s toy Meccano has gone digital, releasing a programmable kit robot that can be controlled by voice recognition. The toymakers say Meccanoid G15 KS is easy to use and is compatible with existing Meccano pieces. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
The VueXL From VX1 Immersive Smartphone Headset!

The VueXL From VX1 Immersive Smartphone Headset!

Rumble (Jan. 22, 2015) The VueXL from VX1 is a product that you install your smartphone in and with the magic of magnification lenses, enlarges your smartphones screen so that it&apos;s like looking at a big screen TV. Check it out! Video provided by Rumble
Powered by NewsLook.com
Analysis: NTSB Wants Better Black Boxes

Analysis: NTSB Wants Better Black Boxes

AP (Jan. 22, 2015) NTSB investigators recommended Thursday that long-distance passenger planes carry improved technology to allow them to be found more easily in a crash, as well as include enhanced cockpit recording technology. (Jan. 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