Science & Research

Grant inspires development of newer, cheaper solar cells

Potential solar cell material could be incorporated into windows, building facades

By
Science & Research Editor
Tuesday, September 15, 2015

When Professor of Material Engineering Nitin Padture arrived at Brown in 2012, he felt his past research had been significant, but that he could start using research to also make a difference. Given the demand for renewable energy, Padture and his team turned to the field of photovoltaics, in which they saw the opportunity to make a strong  impact.

In recognition of the team’s work thus far, the National Science Foundation awarded Padture and his interdisciplinary team a $4 million grant last month.The grant will allow them to build on their exploration of solar energy and launch an outreach program.

Padture points to data from the Department of Energy, which indicates that solar power alone has the potential to fill the demand for renewable energy sources.

According to the data, solar energy could theoretically produce 80,000 gigawatts of electricity per year in the United States, up from the 7.3 gigawatts that are produced today.

But cost remains a continued barrier. Though the cost of silicon solar cells has declined from $60 per watt in 1970 to $1 per watt today and is projected to fall to 50 cents per watt by 2020, fossil fuels like coal cost a mere five cents per watt.

Padture said material scientists can play a role in lowering these costs if they are able to develop solar cells that are cheaper than the prevalent silicon-based solar cells and increase the efficiency with which they convert sunshine into electricity.

But “these types of problems need interdisciplinary solutions,” he added. To this end, the team includes University faculty and students from a range of departments, and they will collaborate with Nebraska Lincoln Laboratory  and partner with Toogaloo College and Rhode Island College.

One facet of Padture’s research has focused on perovskite — a type of crystal structure — as a material for building solar cells. Perovskite is less expensive than silicon and in recent years the solar panels made from this material have become more efficient.

A graduate student in Padture’s lab, Yuanyuan Zhou GS, developed a method to create perovskite crystals at room temperature rather than at higher temperatures, thus utilizing less energy.

Moving forward, the researchers hope to movebeyond the tiny panels designed for research use and make perovskite panels at a size scalable for large-scale manufacturing.

Perovskite panels can also be made in various colors and as thin as one-thousandth the width of a strand of hair, making it possible for people to use them in windows or inconspicuously attach them to the sides of buildings, he said.

In addition to supporting research students and equipment, the grant will fund outreach to primary and secondary schools and support the establishment of public lectures on energy-related topics.

“This is just the beginning,” Padture said. “This gives us the traction to leverage more resources to expand photovoltaics research in Rhode Island.”

Shanhui Fan, professor of electrical engineering at Stanford University, said there are “concerns about reliability” regarding perovskite solar cells that researchers are trying to tackle. Perovskite solar cells are a promising area for research because of gains in efficiency, he said, adding that his own research on solar efficiency is complementary to the project.