Breakthrough in nanowires

In a series of papers, researchers have documented a breakthrough in laser action in semiconductor nanowires and further shown enhanced optical and electronic performance.

Nanowire lasers have potential uses in computing, communications and sensing, and researchers from Technische Universitaet Muenchen have demonstrated laser action in semiconductor nanowires that emit light at technologically useful wavelengths, and shown how to enhance their performance.

“Nanowire lasers could represent the next step in development of smaller, faster, more energy efficient sources of light,” said Professor Jonathan Finley. “But nanowires are also a bit special 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.”

These experimental nanowires emit light in the near-infrared and can be grown directly on silicon presenting opportunities for integrated photonics and optoelectronics. They have a tailored core-shell structure which enables them to act as both lasers generating coherent pulses of light and as waveguides, similar to optical fibres.

The nanowires are fabricated from III-V semiconductors – materials with the right bandgap to emit in the near-IR. They can be grown directly on silicon chips and yield a high-quality material with the potential for high performance.

“At present very few labs in the world have the capability to grow nanowire materials and devices with the precision required,” said Professor Gerhard Abstreiter. “And yet our processes and designs are compatible with industrial production methods for computing and communications.”

The team are now working to better understand the physical phenomena at work in such devices as well as creating electrically injected nanowire lasers, optimising their performance and integrating them with platforms for silicon photonics. The team believes the nanowires could be used in on-chip optical interconnects, optical transistors to speed up computers, and laser arrays with steerable beams.

Abstreiter added: “Experience shows that today’s hero experiment can become tomorrow’s commercial technology, and often does.”

Lasing from individual GaAs-AlGaAs core-shell nanowires up to room temperature. http://www.nature.com/ncomms/2013/131205/ncomms3931/full/ncomms3931.html

High mobility one- and two-dimensional electron systems in nanowire-based quantum heterostructures. http://pubs.acs.org/doi/abs/10.1021/nl403561w

Enhanced luminescence properties of InAs-InAsP core-shell nanowires. http://pubs.acs.org/doi/abs/10.1021/nl403341x