Connect with us

Hi, what are you looking for?

CleanTechnica
The field of solar energy is changing rapidly, with new research, ideas, and results abounding on all sides. One of the many frontiers is the Swiss Federal Institute of Technology Zurich (also known as ETH Zurich, for brevity), where researchers are exploring nanotechnology and the production of hydrogen directly from sunlight.

Clean Power

Better Yield from Solar Harvest

The field of solar energy is changing rapidly, with new research, ideas, and results abounding on all sides. One of the many frontiers is the Swiss Federal Institute of Technology Zurich (also known as ETH Zurich, for brevity), where researchers are exploring nanotechnology and the production of hydrogen directly from sunlight.

The field of solar energy is changing rapidly, with new research, ideas, and results abounding on all sides. One of the many frontiers is the Swiss Federal Institute of Technology Zurich (also known as ETH Zurich, for brevity), where researchers are exploring nanotechnology and the production of hydrogen directly from sunlight.

The researchers at ETH Zurich believe they can significantly increase energy conversion efficiency with new nanomaterials — the current average for the solar cells shimmering on rooftops all over the world is under 20%.

ETH Zurich’s team is working with tiny little structures distinctly smaller than the wavelength of the light they’re converting to energy. The problem as they see it is the presence of so-called “hot electrons.”

When sunlight hits the semi-conductor material, it results in charge carriers — electrons — and the more the better, because that generates more electric current. The wavelength of the light in question directly affects the amount of power that can be generated. The most efficient conversion is at a wavelength of 1000 nanometers, or infrared light. If the wavelength is shorter — like, say, daylight — the electrons respond by carrying an extra jolt of energy (this is what makes them “hot”).

Hot electrons are BAD. They “cool off” — let that extra energy go — within a few billionths of a second, but that extra energy sticks around and just heats up the solar cell. This is no good.

The ETH Zurich team’s idea is to keep the electrons hot until they’ve left the solar cell gridline. In order to force them to retain their extra energy, the team uses nanostructures composed of lead selenide coated with titanium dioxide to expand the energy bandgap the electrons must jump across within the semiconductor material. The larger gap forces the electrons to keep the energy or they won’t be able to pass the barrier.

“Hot film solar cells would be the ultimate solar technology,” says David Norris, professor in the Department of Mechanical Engineering and Technology. “66% conversion efficiency is the theoretical upper limit.”

Wish him luck — 66% sounds pretty impressive from here.

Researchers are working on other ideas as well, including a nanocrystal bilayer for tandem catalysis and thermophotovoltaics. The full text of the article is available in the ETH GLOBE, Nr. 2/June 2011, on page 22.

Source | Picture: Sonnenseite

 
 
 
Appreciate CleanTechnica’s originality and cleantech news coverage? Consider becoming a CleanTechnica Member, Supporter, Technician, or Ambassador — or a patron on Patreon.
 

Don't want to miss a cleantech story? Sign up for daily news updates from CleanTechnica on email. Or follow us on Google News!
 

Have a tip for CleanTechnica, want to advertise, or want to suggest a guest for our CleanTech Talk podcast? Contact us here.
Advertisement
 
Written By

spent 7 years living in Germany and Japan, studying both languages extensively, doing translation and education with companies like Bosch, Nissan, Fuji Heavy, and others. Charis has a Bachelor of Science degree in biology and currently lives in Chicago, Illinois. She also believes that Janeway was the best Star Trek Captain.

Comments

You May Also Like

Clean Power

Pumped hydro already accounts for 93% of utility-scale energy storage in the US, and plans are in the works to build up from there.

Clean Power

New green ammonia project aims to connect green hydrogen dots.

Energy Storage

Flow batteries sport a number of advantages compared to lithium-ion batteries, including the ability to restart quickly after being idled for long periods of...

Clean Power

Hothouse flowers no more: floating offshore wind developers are taking aim at triple-digit megawatt territory now.

Copyright © 2022 CleanTechnica. The content produced by this site is for entertainment purposes only. Opinions and comments published on this site may not be sanctioned by and do not necessarily represent the views of CleanTechnica, its owners, sponsors, affiliates, or subsidiaries.