Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanoparticles used in solar energy conversion

09.08.2002


An enormous source of clean energy is available to us. We see it almost every day. It’s just a matter of harnessing it.



The problem with solar energy is that it has not been inexpensive enough in the past. David Kelley, professor of chemistry at Kansas State University, developed a new type of nanoparticle -- a tiny chemical compound far too small to be seen with the naked eye -- that may reap big dividends in solar power.

Kelley’s team is studying the properties and technical problems of gallium selenide nanoparticles. The properties of the nanoparticle change as the size changes. One of those properties is the part of the light spectrum it absorbs.


"You can make dramatically different colors just by changing the size of the nanoparticles," Kelley said.

Kelley is developing nanoparticles that are just the right size for solar cells -- they can absorb all visible light but nothing from the invisible light at the red end of the spectrum, which would reduce voltage.

"The correct-sized nanoparticles look dark red to black. There is an optimum size and that’s what you want to shoot for," Kelley said.

Today’s solar panels are made with silicon. The silicon usually has impurities, which limits its efficiency. Purifying a chemical is too expensive. For that reason, smaller is better. One can fit as many nanoparticles into a golf ball as one can fit beach balls into the earth.

Only a tiny percentage of a piece of material has impurities. If the entire chunk of material makes one crystal in a solar panel, the crystal will not work. But if that chunk is broken up into 100 tiny nanoparticles, then only the few unlucky nanoparticles with the impurities will not function. All the other nanoparticles will be pure and therefore will work.

Kelley said he is a long way from developing compounds that are comparable to today’s silicon solar cells, because the physics of nanoparticles is so poorly understood. By using gallium selenide, Kelley is laying the groundwork for a similar, but more complex and potentially more effective nanoparticle called indium selenide. It is difficult to make silicon nanoparticles, but indium selenide has great potential for nanoparticle solar cells, Kelley said.

"The idea is to make large, high-output solar voltaic panels that are dirt cheap to produce. It’s only then that the price starts to become competitive with burning fossil fuels," Kelley said.

He nearly had to start from scratch. His team invented gallium selenide nanoparticles. Kelley said he knew six years ago that many semiconductor materials had potential use in solar power, but were not being studied because there were no methods to make them into nanoparticles.

"All these really interesting materials were being ignored and I thought it just can’t be allowed to stay that way," Kelley said.


###
The study on the methods to produce the nanoparticles was published in the journal "Nano Letters" this year. The project was funded by the U.S. Department of Energy’s Solar Photochemistry Program in Basic Energy Sciences.


David Kelley | EurekAlert!

More articles from Power and Electrical Engineering:

nachricht In best circles: First integrated circuit from self-assembled polymer
19.02.2018 | Max-Planck-Institut für Polymerforschung

nachricht System draws power from daily temperature swings
16.02.2018 | Massachusetts Institute of Technology

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Contacting the molecular world through graphene nanoribbons

19.02.2018 | Materials Sciences

When Proteins Shake Hands

19.02.2018 | Materials Sciences

Cells communicate in a dynamic code

19.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>