Skip to Content

Wire Power

One photovoltaic wire could power a sensor; arrays could yield cheaper electricity.
December 18, 2007

This 300-nanometer-wide silicon wire (left) generates electricity from sunlight. Such nano­wire solar cells would initially be useful in tiny sensors, or in robots whose electronics might need built-in power. But arrays of microscopic wires could change the economics of solar power by enabling solar cells built from cheap materials such as low-grade silicon or even iron oxide–rust.

A number of such cheap materials absorb light and generate electrons, but defects in the materials usually “trap” the electrons before they can be collected. Microscopic wires, though, can be made thin enough to allow electrons to slip out easily and generate current, even if the material has defects. And the wires can be long enough to absorb plenty of photons from sunlight hitting them at an angle.

The image is colored to highlight functional layers of the nanowire, which was made in the lab of Harvard University chemist Charles Lieber. The layers are made of silicon modified in ways that give them properties useful for generating and harvesting charged particles. To make solar panels, the microscopic wires could be grown in dense arrays. The below image shows a cross section of a silicon-wire array fabricated in the labs of chemist Nathan Lewis and physicist Harry ­Atwater at Caltech. Each wire is two or three micrometers in diame­ter. Both groups are in the early research stages, but arranging microscopic wires in a forestlike configuration could lead to new materials that harvest sunlight cheaply and efficiently.

Courtesy of Brendan Kayes and Michael Filler

Keep Reading

Most Popular

This new data poisoning tool lets artists fight back against generative AI

The tool, called Nightshade, messes up training data in ways that could cause serious damage to image-generating AI models. 

The Biggest Questions: What is death?

New neuroscience is challenging our understanding of the dying process—bringing opportunities for the living.

Rogue superintelligence and merging with machines: Inside the mind of OpenAI’s chief scientist

An exclusive conversation with Ilya Sutskever on his fears for the future of AI and why they’ve made him change the focus of his life’s work.

How to fix the internet

If we want online discourse to improve, we need to move beyond the big platforms.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.