DEC 13, 2013 12:00 AM PST

Nanowire Lasers Show Promise For Real-World Applications

WRITTEN BY: Jen Ellis
One of the most difficult aspects about nanotechnology advancements is integrating laboratory achievements into real-world applications. Many experiments show promise in the lab, and can theoretically be produced in an industrial environment, but have limiting properties that keep them from making the final leap into commerce.

In the semiconducting world, one of the primary tradeoffs is performance under ambient temperature conditions. With this in mind, scientists at the Technical University of Munich (TUM) in Munich, Germany have developed nanowires containing Group III-V semiconductor materials that can act as nano-scale lasers and operate at room temperature. These light-emitting wonders were introduced in the journal Nature Communications, and further explored in Nano Letters, where improved performance was demonstrated in both electronic and optical applications.

The possible applications are not limited to traditional electronic and optical fields. Nanowires have very high sensitivity (in part because of their inherently large surface-to-volume ratio), and depending on the size of nanowire created, they may be capable of entering biological cells. This combination opens up interesting possibilities in sensors for environmental and biological applications, perhaps allowing effective monitoring of sensitive biosystems that are currently impossible to monitor.
The TUM research team used the more forgiving nature of nanowires (as compared to producing films or bulk crystals) to produce a "core-shell" construction that optimizes the different Group III-V components. The resulting nanowires are about one-thousandth of the thickness of a human hair, and have a bandgap tailored to emit in the near-IR wavelengths (making them well suited for fiber-optics). Further, they can act as both lasers and waveguides.

Since they are capable of being grown directly on silicon wafers, the nanowires are compatible with existing manufacturing processes-and because of their small diameters (around 10-100 nm), issues with mismatching of crystal lattices can be avoided during the growth process. This combination could represent a future breakthrough in industrial-scale silicon-based photonics.

However, it's far too early to declare victory for this technology-for a number of reasons.

The laser output from the TUM nanowires (as well as similar materials reported by the Australian National University) was produced by light stimulation-and in the field electrical stimulation is going to be the most likely mechanism. There's no guarantee that the same performance can be achieved under those conditions.

With respect to manufacturing, the precise growth mechanism will require significant capital equipment investment to achieve tight manufacturing tolerances at higher scales. Currently, there are very few facilities that are capable of producing these materials at all, much less at scale. Basic economics could limit the use to high-value added or military applications. (Even so, other technologies have made similar leaps in the past-if the performance is superior, industry will find a way.)

Of course, safety and regulatory concerns will be another hurdle to overcome-especially for materials small enough to penetrate cells. Expect the US EPA and other regulatory agencies to give this the same scrutiny and restrictions as other nanotechnology advancements, potentially adding extended testing time and costs.

Room-temperature operation and compatibility with existing processes make this technology promising enough to warrant further research. Work is continuing in optimizing processes, exploring electrical activation methods, and integrating and characterizing their performance in typical photonics devices and platforms. Keep an eye on this interesting technology as it tries to make its way from the lab to the marketplace.

Image: NanotechWeb
About the Author
You May Also Like
JUN 08, 2021
Space & Astronomy
Physicists Find Definitive Proof of What Causes the Northern Lights
JUN 08, 2021
Physicists Find Definitive Proof of What Causes the Northern Lights
The auroras that are the northern lights have captured the imagination of people for thousands of years. While theories ...
JUN 23, 2021
Chemistry & Physics
Could willow trees filter wastewater and untreated sewage?
JUN 23, 2021
Could willow trees filter wastewater and untreated sewage?
A new study published in the journal Science of the Total Environment demonstrates the potential of willow tree roots to ...
JUL 30, 2021
Earth & The Environment
Using Iron Waste to Clean Pesticides
JUL 30, 2021
Using Iron Waste to Clean Pesticides
Groundwater is something most people use every day. Whether for drinking, washing, or growing the food you eat, it is pa ...
SEP 02, 2021
Chemistry & Physics
The Future of Room-Temperature Superconductors
SEP 02, 2021
The Future of Room-Temperature Superconductors
It begins with two diamonds, a pinch of carbon, sulfur, and a whiff of hydrogen gas. The result is the world’s fir ...
SEP 06, 2021
Chemistry & Physics
NASA's James Webb Space Telescope is Ready for Space!
SEP 06, 2021
NASA's James Webb Space Telescope is Ready for Space!
With a long set of rigorous tests behind it, the James Webb Space Telescope (JWST), NASA’s next major space telesc ...
SEP 14, 2021
Plants & Animals
Ant Teeth Can Function Like Miniature Metal Tools
SEP 14, 2021
Ant Teeth Can Function Like Miniature Metal Tools
Researchers have discovered the secret to the powerful cutting ability of ants: they have teeth on the outside of their ...
Loading Comments...