Researchers Build Stable Solar Panel Without Silicon

Solar power as an electricity source is growing in the United States, with 7% of Americans using it to run their homes. But scientists are still trying to make the solar panel production process more efficient.

Solar panels are composed of dozens of solar cells, which are usually made of silicon. While silicon is the standard, producing and processing it is energy-intensive, making it costly to build new solar panel manufacturing facilities. Most of the world’s solar cells are made in China, which has an abundance of silicon. To increase solar cell production in the U.S., a new, easily produced domestic material is needed.

“We’re developing technologies that we can easily produce without spending a ton of money on expensive equipment,” said Juan-Pablo Correa-Baena, an associate professor in the School of Materials Science and Engineering.
 

For years, Correa-Baena’s research group has explored using perovskite crystals as an alternative to silicon. A promising and prevalent replacement, perovskite is made of iodine atoms, lead, and organic elements. It is also as efficient as silicon.

However, perovskite has one major drawback: It lasts only about 5% as long as a silicon cell. Compared to silicon’s 20 years, perovskite-made cells deteriorate after a year of use. The material is especially sensitive to hot summer temperatures and can decompose before the solar panel can help a homeowner save on energy costs.

Using a new technology, Correa-Baena’s lab has found a way to stabilize the perovskite solar cells, which are built like a battery. They have one positive and one negative electrode, with the perovskite cell sandwiched between them. Before placing a positive electrode at the top of the cell, the researchers exposed the perovskite to titanium gas under a light vacuum. This process, known as vapor-phase infiltration, embeds titanium into the top layer of the solar cell. The technology is under patent review.

“We've made one of the layers that causes the longevity issue more robust and resilient to especially high temperatures,” Correa-Baena said. “In this process of inserting titanium, we can prevent the degradation process, and then we can test the solar cell on roofs or anywhere.”

Ultimately, the shift from silicon to perovskite crystals in solar cell production could transform the solar industry. The innovative stabilization technique developed by Correa-Baena's team addresses the primary drawback of perovskite cells, making them more viable for long-term use. This progress not only enhances the potential for domestic solar cell production but also supports the broader goal of increasing renewable energy adoption in the United States.

Funding courtesy of U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy Solar Energy Technologies Office.