Researchers unveil new solar cell made from carbon nanotubes that converts more sunlight into power

August 18, 2014 by Bob Yirka report
Researchers unveil new solar cell made from carbon nanotubes that converts more sunlight into power

(Phys.org) —A team of researchers with members from several research facilities in the U.S. has unveiled a new type of solar cell based on single walled carbon nanotubes (SWCNTs). In their paper published in the journal Nano Letters, the team claims they have overcome limitations with such technology resulting in a solar cell that is two times as good at converting sunlight into power as other SWCNT based cells.

Scientists would like to use carbon nanotubes in solar cells because it would mean lighter panels, lower costs and easier to make products. They've been hampered, however, by the limited amount of power that such cells are able to generate. In this new effort the research team claims they've overcome the limitations of prior generations of SWCNTs by adding more chiralities to the nanotubes. Chiralities describe the way atoms are arranged in their hexagonal patterns—different patterns allow for absorbing different portions of the . Most prior efforts have used just one. This new team has added what they call polychiral SWCNTs to their cells which allows for capturing much more of the solar spectrum—most notably, in the near infrared, which other don't make use of at all.

The researchers also added an ability to control the interface between the underlying hole-transport layer and the active photovoltaic layer, allowing the electron and hole pair (excitons) to recombine more efficiently. Taken together the two improvements serve to allow for both higher current and voltage, resulting in record high power conversion efficiency. They report that The National Renewable Energy Laboratory has already certified (by verifying) the performance claimed by the team. But the team isn't done just yet. They want to improve the even more and may do so by testing new materials not used in any other cell.

While it could be awhile before a product is made for sale based on what the team has wrought, their research might cause others in the field to take notice, which could conceivably result in a resurgence of interest in carbon based in general—interest has lagged in recent years as researchers began to doubt they could make them both useful and profitable. Hopefully so, because it would mean less expensive (and lighter) that produce as much power as conventional panels or even more—leading perhaps to a major move from greenhouse gas emitting coal fired to something much cleaner.

Explore further: Future looks bright for carbon nanotube solar cells

More information: Polychiral Semiconducting Carbon Nanotube–Fullerene Solar Cells, Nano Lett., Article ASAP, DOI: 10.1021/nl5027452

Abstract
Single-walled carbon nanotubes (SWCNTs) have highly desirable attributes for solution-processable thin-film photovoltaics (TFPVs), such as broadband absorption, high carrier mobility, and environmental stability. However, previous TFPVs incorporating photoactive SWCNTs have utilized architectures that have limited current, voltage, and ultimately power conversion efficiency (PCE). Here, we report a solar cell geometry that maximizes photocurrent using polychiral SWCNTs while retaining high photovoltage, leading to record-high efficiency SWCNT–fullerene solar cells with average NREL certified and champion PCEs of 2.5% and 3.1%, respectively. Moreover, these cells show significant absorption in the near-infrared portion of the solar spectrum that is currently inaccessible by many leading TFPV technologies.

Related Stories

Future looks bright for carbon nanotube solar cells

June 18, 2013

(Phys.org) —In an approach that could challenge silicon as the predominant photovoltaic cell material, University of Wisconsin-Madison materials engineers have developed an inexpensive solar cell that exploits carbon nanotubes ...

Maximising solar cells

January 22, 2014

(Phys.org) —With silicon solar cells set to become a thing of the past, a Flinders University researcher has developed a novel computer system to find the best emerging carbon nanotubes to fuel the future.

A new stable and cost-cutting type of perovskite solar cell

July 17, 2014

Perovskite solar cells show tremendous promise in propelling solar power into the marketplace. The cells use a hole-transportation layer, which promotes the efficient movement of electrical current after exposure to sunlight. ...

Inexpensive flexible fiber perovskite solar cells

August 4, 2014

(Phys.org) —Textile solar cells are an ideal power source for small electronic devices incorporated into clothing. In the journal Angewandte Chemie, Chinese scientists have now introduced novel solar cells in the form of ...

Towards more efficient solar cells

August 13, 2014

A layer of silicon nanocrystals and erbium ions may help solar cells to extract more energy from the ultraviolet (UV, high-energy) part of the solar spectrum. Experimental physicists from the FOM Foundation, the STW Technology ...

Recommended for you

Reshaping the solar spectrum to turn light to electricity

July 28, 2015

When it comes to installing solar cells, labor cost and the cost of the land to house them constitute the bulk of the expense. The solar cells—made often of silicon or cadmium telluride—rarely cost more than 20 percent ...

Could stronger, tougher paper replace metal?

July 24, 2015

Researchers at the University of Maryland recently discovered that paper made of cellulose fibers is tougher and stronger the smaller the fibers get. For a long time, engineers have sought a material that is both strong (resistant ...

Changing the color of light

July 23, 2015

Researchers at the University of Delaware have received a $1 million grant from the W.M. Keck Foundation to explore a new idea that could improve solar cells, medical imaging and even cancer treatments. Simply put, they want ...

Wafer-thin material heralds future of wearable technology

July 27, 2015

UOW's Institute for Superconducting and Electronic Materials (ISEM) has successfully pioneered a way to construct a flexible, foldable and lightweight energy storage device that provides the building blocks for next-generation ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.