Solarmer Energy Inc. is developing plastic solar cells for portable electronicdevices that will incorporate technology invented at the University of Chicago.
The company is on track to complete a commercial-grade prototype later this year,said Dina Lozofsky, vice president of IP development and strategic alliances atSolarmer. The prototype, a cell measuring eight square inches (50 square centimeters),is expected to achieve 8 percent efficiency and to have a lifetime of at leastthree years.
"New materials with higher efficiencies are really the key in our industry.Plastic solar cells are behind traditional solar-cell technology in terms of theefficiency that it can produce right now," Lozofsky said. "Everyonein the industry is in the 5 percent to 6 percent range."
The invention, a new semiconducting material called PTB1, converts sunlight intoelectricity. Inventors Luping Yu, Professor in Chemistry, and Yongye Liang, aPh.D. student, both at the University of Chicago, and five co-authors describethe technical details of the technology in an online article published Dec. 18,2008, in the Journal of the American Chemical Society.
"Yongye is very knowledgeable and skillful. Very creative," Yu said."He is mainly responsible for the progress of this project."
The active layer of PTB1 is a mere 100 nanometers thick, the width of approximately1,000 atoms. Synthesizing even small amounts of the material is a time-consuming,multi-step process. "You need to make sure what you have is what you thinkyou have," Yu said.
The University licensed the patent rights to the technology to Solarmer last September.The license covers several polymers under development in Yu's laboratory, saidMatthew Martin, a project manager at UChicagoTech, the University's Office ofTechnology and Intellectual Property. A patent is pending.
An advantage of the Chicago technology is its simplicity. Several laboratoriesaround the country have invented other polymers that have achieved efficienciessimilar to those of Yu's polymers, but these require far more extensive engineeringwork to become a viable commercial product.
"We think that our system has potential," Yu said. "The best systemso far reported is 6.5 percent, but that's not a single device. That's two devices."
By combining Solarmer's device engineering expertise with Yu and Liang's semiconductingmaterial, they have been able to push the material's efficiency even higher. Basedin El Monte, Calif., Solarmer was founded in 2006 to commercialize technologydeveloped in Professor Yang Yang's laboratory at the University of California,Los Angeles. The company is developing flexible, translucent plastic solar cellsthat generate low-cost, clean energy from the sun.
Yu began working with Solarmer at the suggestion of UCLA's Yang, a professor ofmaterials science and engineering. Yu's research specialties include the developmentof new polymers, long chains of identical atoms that chemists hook together toform plastics and other materials.
Yu's research program includes funding from the National Science Foundation anda Collaborative Research Seed Grant from the University of Chicago and ArgonneNational Laboratory. Solarmer has entered into a sponsored research agreementwith the University to provide additional support for a postdoctoral researcherin Yu's lab. The company looks forward to the identification of new polymers asa result of this collaboration, Lozofsky said.
Silicon-based solar cells dominate the market today. Industry observers see apromising future for low-cost, flexible solar cells, said UChicagoTech's Martin."If people can make them sufficiently efficient, they may be useful for allsorts of applications beyond just the traditional solar panels on your house rooftop,"he said.
—Prof. Kunle Odunsi
