Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Powerful gallium nitride red light-emitting diodes made with europium and magnesium codoping

27.06.2013
Toyohashi Tech researchers fabricate powerful red light-emitting diodes by codoping GaN with Eu and Mg. The details are described in the June 2013 issue of Toyohashi Tech e-Newsletter: http://www.tut.ac.jp/english/newsletter/index.html
Europium (Eu) doped nitride semiconductors show potential for realization of novel optical devices, such as a low threshold lasers and single photon emitters, due to their sharp line and high efficiency emission.

However, not all the Eu ions in semiconductor are incorporated in optically active sites that can be excited through the GaN host. Therefore, it is important to develop methods to selectively incorporate Eu ions in higher-efficiency optical sites.

Here, Hiroto Sekiguchi and colleagues at Toyohashi University of Technology and Hamamatsu Photonics Ltd have improved the emission intensity from Eu ions by Mg co-doping and fabricated red LEDs with Eu and Mg doped active layer grown by ammonia source MBE.

The optimal Mg co-doping selectively enhanced a specific emission site and contributed to a photoluminescence (PL) intensity increase of more than one order of magnitude. From the ratio of PL integrated intensity at 25 K to that at 300 K, the PL efficiency was determined to be as high as 77%. On the basis of these results, Eu doped GaN based LEDs were fabricated. Clear rectification characteristics with a turn-on voltage of 3.2 V were observed and a pure red emission was observed by the naked eye at room temperature. These results suggest that Eu and Mg doped GaN is expected to be utilized for realizing new nitride-based light-emitting devices.

Further information:
Toyohashi University of Technology,
1-1 Hibarigaoka, Tempaku,
Toyohashi, Aichi Prefecture, 441-8580, JAPAN

Enquiries: International Affairs Division
E-mail: ryugaku@office.tut.ac.jp
TEL: +81-532-44-6577 or +81-532-44-6546
FAX: +81-532-44-6557

About Tokyo Institute of Technology
The Toyohashi University of Technology (Toyohashi Tech) is one of Japan's most innovative and dynamic science and technology based academic institutes. The Toyohashi Tech e-Newsletter is a quarterly publication to update readers on news, research and other activity at the university.

Journal information
Reference:
Author: Hiroto Sekiguchi, Yasufumi Takagi, Tatsuki Otani, Ryota Matsumura, Hiroshi Okada, and Akihiro WakaharaTitle: Red-Light-Emitting Diodes with Site-Selective Eu-Doped GaN Active Layer Journal: Jpn. J. Appl. Phys. 52 (2013)DOI: 10.7567/JJAP.52.08JH01

Fig. 1 Typical emission image of Eu doped GaN based LED

Affiliation(s): Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology.

Adarsh Sandhu | Research asia research news
Further information:
http://www.tut.ac.jp/english/
http://www.tut.ac.jp/english/newsletter/research_highlights/research03.html#sec1

More articles from Power and Electrical Engineering:

nachricht Ultrathin device harvests electricity from human motion
24.07.2017 | Vanderbilt University

nachricht Stanford researchers develop a new type of soft, growing robot
21.07.2017 | Stanford University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Ultrathin device harvests electricity from human motion

24.07.2017 | Power and Electrical Engineering

Scientists announce the quest for high-index materials

24.07.2017 | Materials Sciences

ADIR Project: Lasers Recover Valuable Materials

24.07.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>