Skip to Content

Sunlight Absorber

A nanoscale pattern could lead to more efficient solar cells
February 21, 2012

Source: “Broadband 
Polarization-Independent Resonant Light Absorption Using Ultrathin Plasmonic Superabsorbers”
Harry Atwater et al.
Nature
Communications 2: 517

Results: Thin films of silver ordinarily absorb only 5 percent of visible light. By applying a pattern of nanoscale shapes to such a surface, researchers increased absorption to 70 percent. The patterned film absorbs light from the entire visible spectrum and from almost any angle.

Why it matters: The advance could lead to solar cells that are far thinner and cheaper than conventional ones, because less semiconductor material would be needed to absorb sunlight. Researchers have known that nanoscale patterns can greatly enhance light absorption by gathering light waves the way antennas gather radio waves. But these patterns typically absorb only light of certain wavelengths, allowing most of the solar spectrum to escape. That makes them impractical for use in solar cells. The researchers have demonstrated that their patterns can be used to absorb a wide range of wavelengths, opening the door for their use in photovoltaic devices.

Methods: The researchers used lithography to carve patterns of tiny wedge shapes placed end to end. The narrow end of the wedges can absorb short wavelengths at the blue end of the spectrum, and the wider end absorbs longer-wavelength red light.

Next Steps: The researchers are working to apply the nanoscale design to materials used in solar cells. In recent, unpublished experiments, they showed that the patterns can allow thin films of silicon to absorb as much light as unpatterned silicon films 25 times as thick.

Keep Reading

Most Popular

individual aging affects covid outcomes concept
individual aging affects covid outcomes concept

Anti-aging drugs are being tested as a way to treat covid

Drugs that rejuvenate our immune systems and make us biologically younger could help protect us from the disease’s worst effects.

Europe's AI Act concept
Europe's AI Act concept

A quick guide to the most important AI law you’ve never heard of

The European Union is planning new legislation aimed at curbing the worst harms associated with artificial intelligence.

Uber Autonomous Vehicles parked in a lot
Uber Autonomous Vehicles parked in a lot

It will soon be easy for self-driving cars to hide in plain sight. We shouldn’t let them.

If they ever hit our roads for real, other drivers need to know exactly what they are.

crypto winter concept
crypto winter concept

Crypto is weathering a bitter storm. Some still hold on for dear life.

When a cryptocurrency’s value is theoretical, what happens if people quit believing?

Stay connected

Illustration by Rose WongIllustration 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.