Nitin Padture, a professor of engineering and director of Brown’s Institute for Molecular and Nanoscale Innovation, will deliver a virtual Presidential Faculty Award lecture on Thursday, April 8. His presentation, titled “The Promise of Innovations in Solar Photovoltaics,” will draw on his research in developing next-generation solar technologies.
In recent years, Padture has focused his research on a class of crystalline materials called perovskites, which have emerged as a promising alternative to traditional silicon for making solar cells. Perovskite cells are less expensive to produce than silicon, yet are almost as efficient in converting sunlight to electricity. Perovskites can also be made into very thin, nearly transparent films. That raises the possibility of energy-producing windows or flexible solar panels incorporated in tents, backpacks and elsewhere.
“Solar is really leading the way in terms of renewable energy right now, and part of the reason is that the cost of solar has been steadily declining,” Padture said. “But that decline is starting to level off now because of some fixed costs associated with silicon, and that’s where perovskites come in. They’re Earth-abundant and inexpensive, so they could play a role in making pennies-per-watt energy attainable.”
Padture’s research focuses on ways of bringing perovskite technology from the lab to the market. As promising as perovskites are, there are still challenges to overcome before they’re ready for prime time. For example, the crystalline structure of the materials is fragile and degrades when exposed to the environment. Another issue has to do with layering of components within perovskite solar cells. The interfaces between those layers are problematic weak points that can reduce the cell’s performance and durability.
Padture’s research group has won two new grants — $1.5 million from the U.S. Department of Energy and $480,000 from the National Science Foundation — to address some of these problems. To improve stability, Padture is developing ways of making perovskite grains larger. Larger grains make for fewer grain boundaries, which are where perovskite cells are most vulnerable to degradation. Padture’s team is making progress on the interface problem as well.
“We’ve chosen the weakest interface and are developing a kind of molecular glue that would toughen the interface while also increasing the efficiency of the cell,” Padture said.
In addition to his research, Padture also plans to discuss the broader landscape of solar energy. There’s been no shortage of technical innovation in improving the performance and lowering the cost of solar technology. But that technical innovation needs to be matched with financial innovation and systems integration to sustain grid-scale solar, Padture says.
“Climate change is making the expansion of solar on a grand scale more and more critical,” he said. “But getting there is going to require science and technology people working with finance and public policy people to better incorporate solar on a national scale.”
The lecture will take place on Thursday, April 8, at 4 p.m. EDT. The virtual event is free and open to the public, but advance registration is required.