The February 2023 issue of IEEE Spectrum is here!

Close bar

Researchers Discover New Structure Inside Nanowires

In the corners of hexagonal nanowires researchers discover a new space for electrons and holes

2 min read
Researchers Discover New Structure Inside Nanowires
Howard Jackson, the University of Cincinnati

Nanowires made from III-V semiconductors like indium gallium arsenide are having a bit of run of late. Yesterday, I reported on a new method for growing them on graphene.

Now researchers at the University of Cincinnati have discovered that a newly developed architecture for semiconductor nanowires has a hidden nook in which to find electrons and holes. The discovery opens up a new understanding of the fundamental physics of nanowires.

The research, which was published in the journal Nano Letters (“Optical, Structural, and Numerical Investigations of GaAs/AlGaAs Core–Multishell Nanowire Quantum Well Tubes”), involved a host of characterization and measurement techniques.

University of Cincinnati physics professors Howard Jackson and Leigh Smith, who together led the research, believe that applications of this new structure could range from solar cells to environmental sensors.

“This kind of structure in the gallium arsenide/aluminum gallium arsenide system had not been achieved before,” Jackson said in a press release. “It’s new in terms of where you find the electrons and holes, and spatially it’s a new structure.”

The researchers grew a quantum well tube around the inner core of the nanowire. With this new architecture, they discovered that electrons were distributed in an unusual way around the facets of the hexagonal nanowire.

“Having the faceting really matters. It changes the ballgame,” Jackson said in the release. “Adjusting the quantum well tube width allows you to control the energy—which would have been expected—but in addition we have found that there’s a highly localized ground state at the corners which then can give rise to true quantum nanowires.”

The nanowires reportedly have a high quantum efficiency that means they should have a very high electrical sensitivity to light, making them potentially ideal for photovoltaic applications.

While the researchers believe that the impact of these nanowires may still be somewhat far off, based on the preliminary stage of this line of research, they think it should present a new paradigm for understanding the fundamental physics surrounding nanowires.

Photo: Howard Jackson, the University of Cincinnati

The Conversation (0)

Two Startups Are Bringing Fiber to the Processor

Avicena’s blue microLEDs are the dark horse in a race with Ayar Labs’ laser-based system

5 min read
Diffuse blue light shines from a patterned surface through a ring. A blue cable leads away from it.

Avicena’s microLED chiplets could one day link all the CPUs in a computer cluster together.

Avicena

If a CPU in Seoul sends a byte of data to a processor in Prague, the information covers most of the distance as light, zipping along with no resistance. But put both those processors on the same motherboard, and they’ll need to communicate over energy-sapping copper, which slow the communication speeds possible within computers. Two Silicon Valley startups, Avicena and Ayar Labs, are doing something about that longstanding limit. If they succeed in their attempts to finally bring optical fiber all the way to the processor, it might not just accelerate computing—it might also remake it.

Both companies are developing fiber-connected chiplets, small chips meant to share a high-bandwidth connection with CPUs and other data-hungry silicon in a shared package. They are each ramping up production in 2023, though it may be a couple of years before we see a computer on the market with either product.

Keep Reading ↓Show less