From 40.7 to 42.8 % Solar Cell Efficiency

University of Delaware-led team sets solar cell record, joins DuPont on $100 million project.

Using a novel technology that adds multiple innovations to a very high-performance crystalline silicon solar cell platform, a consortium led by the University of Delaware (UD) has achieved a record-breaking combined solar cell efficiency of 42.8 percent. The current record of 40.7 percent was attained in December 2006 by Boeing's Spectrolab, Inc.

The research was led by Allen Barnett, principal investigator and UD professor of electrical and computer engineering, and Christiana Honsberg, co-principal investigator and associate professor of electrical and computer engineering. The two direct the University's High Performance Solar Power Program and have been working to achieve the 50 percent efficiency goal set by the Defense Advanced Research Projects Agency (DARPA).

Barnett and Honsberg said that reaching the 42.8 percent mark is a significant advance in solar cell efficiency, particularly given the unique small and portable architecture being used by the consortium and the short time?21 months?in which it was developed.

Honsberg said the previous best of 40.7 percent efficiency was achieved with a high concentration device that requires sophisticated tracking optics and features a concentrating lens the size of a table and more than 30 centimeters, or about 1 foot, thick. The UD consortium's devices are potentially far thinner at less than 1 centimeter.

"This is a major step toward our goal of 50 percent efficiency," Barnett said. "The percentage is a record under any circumstance, but it's particularly noteworthy because it's at low concentration, approximately 20 times magnification. The low profile and lack of moving parts translates into portability, which means these devices easily could go on a laptop computer or a rooftop."

Honsberg said the advance of 2 percentage points is noteworthy in a field where gains of 0.2 percent are the norm and gains of 1 percent are seen as significant breakthroughs.

"This achievement is the direct result of the new architecture we developed under the DARPA program," Barnett and Honsberg said. "By integrating the optical design with the solar cell design, we have entered previously unoccupied design space leading to a new paradigm about how to make solar cells, how to use them, and what they can do."

In November 2005, the UD-led consortium received approximately $13 million in funding for the initial phases of the DARPA Very High Efficiency Solar Cell (VHESC) program to develop affordable portable solar cell battery chargers.

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By: Renewable Energy Access

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