Carbon Nanotubes Serve as Funnel for Photons on Solar Panels

While solar concentrator research interest grows, one wonders if commercializtion will actually follow

2 min read
Carbon Nanotubes Serve as Funnel for Photons on Solar Panels

Nothing excites the imagination of the general public or researchers in the area of alternative energy like solar power does. You can explain until you’re blue in the face how wind power is cheaper per Kwh than solar, or how nanotech is really having an impact now on saving energy as opposed to generating it.

But it all hardly seems to matter. People want to know how nanotech is going to enable solar power. The latest news item comes out of MIT where researchers have formed carbon nanotubes into a kind of antenna that focuses photons onto photovoltaic cells and reportedly concentrates solar energy 100 times more than a regular cell.

According to Michael Strano, the leader of the research team and Charles and Hilda Roddey Associate Professor of Chemical Engineering at MIT, this development could result in smaller solar arrays.

“Instead of having your whole roof be a photovoltaic cell, you could have little spots that were tiny photovoltaic cells, with antennas that would drive photons into them,” says Michael Strano in the article.

The work was originally published in the Sept. 12 online edition of the journal Nature Materials.

The antennas are made of about 30 billion carbon nanotubes and resemble a fibrous strand with dimensions of 10 micrometers long and four micrometers thick. The fiber has different bandgaps. The inner layer of the fiber has a small bandgap while the outerlayer have a higher bandbap. So when photons hit the antenna all the excitons flow to the center of the fiber thereby concentrating them.

While this is all very far off from even a full-fledged prototype since the researchers have not yet built a photovoltaic cell that could use the antenna, it seems that commercial considerations are already being taken into account with concerns about the price per pound of single-walled carbon nanotubes being discussed.

One would think that a discussion of economic issues like price of raw materials and phrases like “100 times” better than existing technologies would interest funding types. But likely they see 10 years before a ROI and myriad competing technologies and shrug.

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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.


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.

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