Jun 19, 2015
Professor Sarah Tolbert
UCLA research team’s development of new storage technology that is capable of storing solar energy for up to several weeks was recently featured in Science.
 
The research team, led by Prof. Sarah Tolbert, includes several members of the UCLA Department of Chemistry & Biochemistry: graduate students Rachel Huber & Amy Ferreira (Tolbert Group), Robert Thompson (Tolbert/Rubin Groups), Nicholas Knutson & Daniel Kilbride (Ruben Group); researchers Dr. Lekshmi Sudha Devi, Dr. J. Reddy Challa (Schwartz Group); and faculty Prof. Benjamin Schwartz and Prof. Yves Rubin. The assembled structure was imaged by UCLA’s Electron Imaging Center for NanoMachines by Prof. Hong Zhou and graduate student Daniel Toso of the California NanoSystems Institute.
 
Senior co-authors UCLA Chemistry and Biochemistry faculty members Sarah Tolbert, Ben Schwartz, and Yves Rubin. 
 
The paper titled "Long-lived photoinduced polaron formation in conjugated polyelectrolyte-fullerene assemblies" was published in the June 19th issue of Science.
 
From UCLA Newsroom (by Melody Pupols):
 
The scientists devised a new arrangement of solar cell ingredients, with bundles of polymer donors (green rods) and neatly organized fullerene acceptors (purple, tan).  Image: UCLA Chemistry
 
UCLA chemists devise technology that could transform solar energy storage
 
The materials in most of today’s residential rooftop solar panels can store energy from the sun for only a few microseconds at a time. A new technology developed by chemists at UCLA is capable of storing solar energy for up to several weeks — an advance that could change the way scientists think about designing solar cells.
 
The findings are published June 19 in the journal Science.
 
The new design is inspired by the way that plants generate energy through photosynthesis.
 
“Biology does a very good job of creating energy from sunlight,” said Sarah Tolbert, a UCLA professor of chemistry and one of the senior authors of the research. “Plants do this through photosynthesis with extremely high efficiency.”
 
“In photosynthesis, plants that are exposed to sunlight use carefully organized nanoscale structures within their cells to rapidly separate charges — pulling electrons away from the positively charged molecule that is left behind, and keeping positive and negative charges separated,” Tolbert said. “That separation is the key to making the process so efficient.”
 
To capture energy from sunlight, conventional rooftop solar cells use silicon, a fairly expensive material.  There is currently a big push to make lower-cost solar cells using plastics, rather than silicon, but today’s plastic solar cells are relatively inefficient, in large part because the separated positive and negative electric charges often recombine before they can become electrical energy.
 
“Modern plastic solar cells don’t have well-defined structures like plants do because we never knew how to make them before,” Tolbert said. “But this new system pulls charges apart and keeps them separated for days, or even weeks. Once you make the right structure, you can vastly improve the retention of energy.”
 
Read entire UCLA Newsroom article here.
 
In the short time since being published, the research has already been reported on widely by many news sources: ScienceDaily, Phys.org, R&D, EurekAlert (American Association for the Advancement of Science), NanoWerk, ECN, Innovation ReportTG Techno, DeepStuff.org, Green Energy Investing, MyScience, Product Design and Development.
 
 
 
Photo credits: Tolbert & Schwartz (Reed Hutchinson/UCLA), Rubin (courtesy of Yves Rubin)