Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Laser light at useful wavelengths from semiconductor nanowires

05.12.2013
Nanowire lasers could work with silicon chips, optical fibers, even living cells

Thread-like semiconductor structures called nanowires, so thin that they are effectively one-dimensional, show potential as lasers for applications in computing, communications, and sensing.


This micrograph shows a forest of III-V semiconductor nanowires standing, as grown, on a silicon substrate.

Credit: WSI/TUM

Scientists at the Technische Universitaet Muenchen (TUM) have demonstrated laser action in semiconductor nanowires that emit light at technologically useful wavelengths and operate at room temperature. They now have documented this breakthrough in the journal Nature Communications and, in Nano Letters, have disclosed further results showing enhanced optical and electronic performance.

"Nanowire lasers could represent the next step in the development of smaller, faster, more energy-efficient sources of light," says Prof. Jonathan Finley, director of TUM's Walter Schottky Institute. Potential applications include on-chip optical interconnects or even optical transistors to speed up computers, integrated optoelectronics for fiber-optic communications, and laser arrays with steerable beams. "But nanowires are also a bit special," Finley adds, "in that they are very sensitive to their surroundings, have a large surface-to-volume ratio, and are small enough, for example, to poke into a biological cell." Thus nanowire lasers could also prove useful in environmental and biological sensing.

These experimental nanowire lasers emit light in the near-infrared, approaching the "sweet spot" for fiber-optic communications. They can be grown directly on silicon, presenting opportunities for integrated photonics and optoelectronics. And they operate at room temperature, a prerequisite for real-world applications.

Tailored in the lab, with an eye toward industry

Tiny as they are – a thousand times thinner than a human hair – the nanowire lasers demonstrated at TUM have a complex "core-shell" cross-section with a profile of differing semiconductor materials tailored virtually atom by atom.

The nanowires' tailored core-shell structure enables them to act both as lasers, generating coherent pulses of light, and as waveguides, similar to optical fibers. Like conventional communication lasers, these nanowires are made of so-called III-V semiconductors, materials with the right "bandgap" to emit light in the near-infrared. A unique advantage, Finley explains, is that the nanowire geometry is "more forgiving than bulk crystals or films, allowing you to combine materials that you normally can't combine." Because the nanowires arise from a base only tens to hundreds of nanometers in diameter, they can be grown directly on silicon chips in a way that alleviates restrictions due to crystal lattice mismatch – thus yielding high-quality material with the potential for high performance.

Put these characteristics together, and it becomes possible to imagine a path from applied research to a variety of future applications. A number of significant challenges remain, however. For example, laser emission from the TUM nanowires was stimulated by light – as were the nanowire lasers reported almost simultaneously by a team at the Australian National University – yet practical applications are likely to require electrically injected devices.

Nanowire lasers: a technological frontier with bright prospects

The newly published results are largely due to a team of scientists who are beginning their careers, under the guidance of Dr. Gregor Koblmueller and other senior researchers, at the frontier of a new field. Doctoral candidates including Benedikt Mayer, Daniel Rudolph, Stefanie Morkötter and Julian Treu combined their efforts, working together on photonic design, material growth, and characterization using electron microscopy with atomic resolution.

Ongoing research is directed toward better understanding the physical phenomena at work in such devices as well as toward creating electrically injected nanowire lasers, optimizing their performance, and integrating them with platforms for silicon photonics.

"At present very few labs in the world have the capability to grow nanowire materials and devices with the precision required," says co-author Prof. Gerhard Abstreiter, founder of the Walter Schottky Institute and director of the TUM Institute for Advanced Study. "And yet," he explains, "our processes and designs are compatible with industrial production methods for computing and communications. Experience shows that today's hero experiment can become tomorrow's commercial technology, and often does."

This research was supported in part by the German Excellence Initiative through the TUM Institute for Advanced Study and the Excellence Cluster Nanosystems Initiative Munich (NIM); by the German Research Foundation (DFG) through Collaborative Research Center SFB 631; by the European Union through a Marie Curie European Reintegration Grant, the QUROPE project SOLID, and the EU-MC network INDEX; by a CINECA award under the ISCRA initiative; and by a grant from Generalitat Valenciana.

Publications:

Lasing from individual GaAs-AlGaAs core-shell nanowires up to room temperature. Benedikt Mayer, Daniel Rudolph, Joscha Schnell, Stefanie Morkoetter, Julia Winnerl, Julian Treu, Kai Mueller, Gregor Bracher, Gerhard Abstreiter, Gregor Koblmueller, and Jonathan J. Finley. Nature Communications, 5 Dec. 2013. DOI: 10.1038/ncomms3931

High mobility one- and two-dimensional electron systems in nanowire-based quantum heterostructures. Stefan Funk, Miguel Royo, Ilaria Zardo, Daniel Rudolph, Stefanie Morkoetter, Benedikt Mayer, Jonathan Becker, Alexander Bechtold, Sonja Matich, Markus Doeblinger, Max Bichler, G. Koblmueller, Jonathan J. Finley, Andrea Bertoni, Guido Goldoni, and Gerhard Abstreiter. Nano Letters Just Accepted Manuscript, 25 Nov. 2013. DOI: dx.doi.org/10.1021/nl403561w

Enhanced luminescence properties of InAs-InAsP core-shell nanowires. Julian Treu, Michael Bormann, Hannes Schmeiduch, Markus Doeblinger, Stefanie Morkoetter, Sonja Matich, Peter Wiecha, Kai Saller, Benedikt Mayer, Max Bichler, Markus Christian Amann, Jonathan Finley, Gerhard Abstreiter, and G. Koblmueller. Nano Letters Just Accepted Manuscript, 25 Nov. 2013. DOI: dx.doi.org/10.1021/nl403341x

Contact:

Prof. Jonathan Finley
Technische Universitaet Muenchen
Walter Schottky Institute
Am Coulombwall 4
85748 Garching, Germany
Tel: +49 89 289 12770
jonathan.finley@wsi.tum.de
http://www.wsi.tum.de/
Prof. Gerhard Abstreiter
Technische Universitaet Muenchen
TUM Institute for Advanced Study
Lichtenbergstrasse 2 a
85748 Garching, Germany
Tel: +49 89 289 10555
gerhard.abstreiter@zv.tum.de
http://www.tum-ias.de/
Technische Universitaet Muenchen (TUM) is one of Europe's leading research universities, with around 500 professors, 10,000 academic and non-academic staff, and 35,000 students. Its focus areas are the engineering sciences, natural sciences, life sciences and medicine, reinforced by schools of management and education. TUM acts as an entrepreneurial university that promotes talents and creates value for society. In that it profits from having strong partners in science and industry. It is represented worldwide with a campus in Singapore as well as offices in Brussels, Cairo, Mumbai, Beijing, and Sao Paulo. Nobel Prize winners and inventors such as Rudolf Diesel and Carl von Linde have done research at TUM. In 2006 and 2012 it won recognition as a German "Excellence University." In international rankings, TUM regularly places among the best universities in Germany.

Patrick Regan | EurekAlert!
Further information:
http://www.tum.de

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>