Navigation Links
New solar energy material captures every color of the rainbow
Date:10/16/2008

COLUMBUS, Ohio -- Researchers have created a new material that overcomes two of the major obstacles to solar power: it absorbs all the energy contained in sunlight, and generates electrons in a way that makes them easier to capture.

Ohio State University chemists and their colleagues combined electrically conductive plastic with metals including molybdenum and titanium to create the hybrid material.

"There are other such hybrids out there, but the advantage of our material is that we can cover the entire range of the solar spectrum," explained Malcolm Chisholm, Distinguished University Professor and Chair of the Department of Chemistry at Ohio State.

The study appears in the current issue of the Proceedings of the National Academy of Sciences (PNAS).

Sunlight contains the entire spectrum of colors that can be seen with the naked eye -- all the colors of the rainbow. What our eyes interpret as color are really different energy levels, or frequencies of light. Today's solar cell materials can only capture a small range of frequencies, so they can only capture a small fraction of the energy contained in sunlight.

This new material is the first that can absorb all the energy contained in visible light at once.

The material generates electricity just like other solar cell materials do: light energizes the atoms of the material, and some of the electrons in those atoms are knocked loose.

Ideally, the electrons flow out of the device as electrical current, but this is where most solar cells run into trouble. The electrons only stay loose for a tiny fraction of a second before they sink back into the atoms from which they came. The electrons must be captured during the short time they are free, and this task, called charge separation, is difficult.

In the new hybrid material, electrons remain free much longer than ever before.

To design the hybrid material, the chemists explored different molecular configurations on a computer at the Ohio Supercomputer Center. Then, with colleagues at National Taiwan University, they synthesized molecules of the new material in a liquid solution, measured the frequencies of light the molecules absorbed, and also measured the length of time that excited electrons remained free in the molecules.

They saw something very unusual. The molecules didn't just fluoresce as some solar cell materials do. They phosphoresced as well. Both luminous effects are caused by a material absorbing and emitting energy, but phosphorescence lasts much longer.

To their surprise, the chemists found that the new material was emitting electrons in two different energy states -- one called a singlet state, and the other a triplet state. Both energy states are useful for solar cell applications, and the triplet state lasts much longer than the singlet state.

Electrons in the singlet state stayed free for up to 12 picoseconds, or trillionths of a second -- not unusual compared to some solar cell materials. But electrons in the triplet state stayed free 7 million times longer -- up to 83 microseconds, or millionths of a second.

When they deposited the molecules in a thin film, similar to how they might be arranged in an actual solar cell, the triplet states lasted even longer: 200 microseconds.

"This long-lived excited state should allow us to better manipulate charge separation," Chisholm said.

At this point, the material is years from commercial development, but he added that this experiment provides a proof of concept -- that hybrid solar cell materials such as this one can offer unusual properties.


'/>"/>

Contact: Malcolm Chisholm
Chisholm.4@osu.edu
614-292-7216
Ohio State University
Source:Eurekalert

Related biology technology :

1. Understanding the science of solar-based energy: more researchers are better than one
2. Flexible nanoantenna arrays capture abundant solar energy
3. Perfecting a solar cell by adding imperfections
4. UC San Diego nanostructures will raise thin-film solar cell efficiency
5. Nanowires may boost solar cell efficiency, UC San Diego engineers say
6. New efficiency record for solar cells
7. Special coating greatly improves solar cell performance
8. Solar cell directly splits water for hydrogen
9. Energy Conversion Devices and United Solar Ovonic Enter Into New $55 Million Secured Credit Facility Agreements
10. Solar energy technology licensed
11. New nanostructured thin film shows promise for efficient solar energy conversion
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/22/2016)... Research and Markets has announced the addition of the ... The global biomarkers market has ... The market is expected to grow at a five-year compound annual ... $50.6 billion in 2015 to $96.6 billion in 2020. ... to 2020) are discussed. As well, new products approved in 2013 ...
(Date:6/22/2016)... LOS ANGELES , June 22, 2016   ... an SNNLive Video Interview with Dr. Nader Pourhassan ... a biotechnology company focused on the clinical development and ... and prevention of HIV infection, according to the company,s ... was recorded on Tuesday, June 7 th , 2016, ...
(Date:6/22/2016)... DIEGO , June 22, 2016   ViaCyte, ... first pluripotent stem cell-derived islet replacement therapy for the ... presentations at ISSCR 2016 Annual Meeting.  ISSCR 2016, the ... to 25th at Moscone West in San Francisco.  ... of the presentations are as follows:Event: , Focus Session: ...
(Date:6/22/2016)... (PRWEB) , ... June 22, 2016 , ... ... at placing a spotlight on immigrant achievements and contributions to North Texas and ... most important contributors from the immigrant community to the civic and economic vitality ...
Breaking Biology Technology:
(Date:6/16/2016)... June 16, 2016 The ... expected to reach USD 1.83 billion by 2024, ... Research, Inc. Technological proliferation and increasing demand in ... expected to drive the market growth. ... The development of advanced multimodal techniques for ...
(Date:6/3/2016)... LONDON , June 3, 2016 /PRNewswire/ ... Transport Management) von Nepal ... ,Angebot und Lieferung hochsicherer geprägter Kennzeichen, einschließlich ... weltweit führend in der Produktion und Implementierung ... an der Ausschreibung im Januar teilgenommen, aber ...
(Date:5/24/2016)... Ampronix facilitates superior patient care by providing unparalleled technology to leaders of the medical ... premium product recently added to the range of products distributed by Ampronix. ... ... ... Ampronix News ...
Breaking Biology News(10 mins):