Engineering professor advances quest for efficient solar power

In Vikram Dalal's 37 years of researching solar technology, the efficiency of thin film solar cells for homes and buildings has improved from 1 percent to about 7 percent.

Dalal, the Thomas M. Whitney Professor of Electrical and Computer Engineering at Iowa State University and director of the university's Microelectronics Research Center, is hoping his latest multidisciplinary research project could boost that efficiency to about 10 percent.

That would mean better solar cell technology that could be patented and licensed by Iowa State, a competitive edge for an Ames-based company collaborating on the project and clean, green energy for all of us.

The three-year research project is supported by a $1.69 million grant from the Iowa Power Fund, a state program to support energy innovation and independence. The project supports the work of Dalal and six other Iowa State faculty members plus eight graduate students. The Iowa Energy Center is also supporting some of Dalal's solar research and he expects that work to contribute to the power fund project.

"We are very excited about this project," said Dalal. "We want to help Iowa become a major producer of solar products that can be sold all over the world. That's what I want do to. I want to help Iowa companies become world-class producers of solar technology."

The project has three primary goals:

• Study, characterize and optimize new silicon alloys that can be used in photovoltaic cells that convert sunlight directly into electricity. Dalal said as new materials are developed, researchers have to figure out how they can be used in solar applications.

• Develop new solar cell structures that optimize the performance of the new materials. Dalal said there is no universal design for solar devices, so new materials mean new structures.

• And, study how semiconductors based on organic molecules can be used in solar applications. Dalal said organic molecules – substances that are found in living things and contain carbon-hydrogen bonds – are very good at absorbing light and could be the future of solar technology.

Working with Dalal on the project are Rana Biswas, an adjunct research associate professor of physics and astronomy; Sumit Chaudhary, an assistant professor of electrical and computer engineering; Malika Jeffries-El, an assistant professor of chemistry; Jaeyoun Kim, an assistant professor of electrical and computer engineering; Joseph Shinar, professor and chair of physics and astronomy; and Ruth Shinar, an adjunct professor of electrical and computer engineering.

The researchers are collaborating with PowerFilm Inc. of Ames and Micron Technology Inc. of Boise, Idaho.

The project includes work in the maturing field of thin film silicon-based photovoltaic technology. And it includes work in the emerging field of organic semiconductors.

Dalal said Iowa State has hired the people and is developing the expertise to make it a leader in the research and development of the new technology.

"Looking 20 years out, it's very clear that organic semiconductors will be a major player in photovoltaic technology," he said. "The technology is in its infancy. And if we don't nurture a technology in its infancy, how do we grow a mature technology? I'm hoping Iowa State can become a leader in this field and help make a smooth transition from our current technology."

That current technology has been a booming business. The Solar Energy Industries Association based in Washington, D.C., reported that the photovoltaic market in the United States grew by more than 48 percent in 2007 and U.S. solar manufacturing grew by 74 percent in 2007. The U.S. currently ranks fourth in the world for installed solar power (behind Germany, Japan and Spain). Solarbuzz, an international solar energy research and consulting company based in San Francisco, reports the photovoltaic industry generated $17.2 billion in global revenues in 2007.

Dalal is hoping the research at Iowa State can contribute to the continued growth of solar energy, making it a major energy option for the future.

"Our whole objective is to achieve greater solar efficiency without sacrificing cost," he said. "We want to do this better and cheaper. Only then can solar penetrate the large-scale utility market."

Photo by Bob Elbert/Iowa State University
Iowa State University's Vikram Dalal has worked nearly four decades to improve the performance of solar cells. His goal is to boost efficiency without raising costs.