The principal investigator of a European project to make larger and more stable solar modules using a promising material called perovskite has joined the Huang Group as a visiting scholar in the department of applied physical sciences.

Luigi Angelo Castriotta, who created the three-year project—Exploiting Flexible Perovskites Solar Technologies, or EFESO—with funding from a Global PostDoctoral Fellowship from Marie Skłodowska-Curie Actions, aims to improve how solar modules are made on flexible substrates, find ways to trap harmful lead particles, and make the modules safer with the use of special protective coatings and novel additive materials that help electricity flow through them.

“Perovskite solar technology is a promising technology but still in the development stage,” said Castriotta, who is spending 21 months at UNC-Chapel Hill. “We want to make it ready for commercial use as soon as possible, but first we want to ensure that these solar modules pass strict tests for efficiency and potential harmful lead.”

Castriotta, whose expertise is in laser design processes, interface engineering and the fabrication of stable flexible perovskite solar modules, is working under the guidance of Jinsong Huang, Louis D. Rubin, Jr. Distinguished Professor. The Huang Group’s current research interest is to understand how perovskites function at a fundamental level and to make perovskite solar panels more efficient, last longer and on a large scale.

“I am glad to host Luigi’s research at UNC,” said Huang. “He is energetic, smart and easy to work with. He helps with supervising undergraduate students, and we appreciate how well he has integrated into the group.”

Over the years, scientists have figured out how to make perovskite solar cells much more efficient; however, they can easily break or degrade. Unlike silicon, which needs high temperatures to be made into solar cells, perovskites can be made at room temperature because they have a unique crystalline structure that allows them to form easily under ambient conditions.

Castriotta is probing the use of special coatings consisting of encapsulants or sealants to shield the perovskite material from moisture, oxygen and UV radiation, which can degrade the performance of solar cells over time, as well as transparent polymer materials to provide flexibility to the solar modules, allowing them to bend or conform to different shapes without compromising their performance.

To prevent harmful lead from leaching out of perovskite solar modules, Castriotta said he and the Huang Group are testing methods that include introducing dopant materials—substances that modify electrical or optical properties—into the perovskite structure to trap lead ions and prevent them from migrating out of the material, and modifying the interfaces between different layers of the solar module to create barriers restricting the movement of the lead ions.

“Uncontrolled movement of lead ions can result in unwanted chemical reactions or changes within the solar panel, which can reduce its efficiency and power output,” said Castriotta. “By restricting their movement, we can maintain the integrity of the device’s structure and optimize its performance.”

In addition to the Huang Group, Castriotta is collaborating with the following research centers that work on upscaling perovskite solar technology worldwide: Saule Technologies, a high-tech company based in Poland, and the Centre for Hybrid and Organic Solar Energy within the Department of Electronic Engineering of the University of Rome Tor Vergata in Italy, which is Castriotta’s current affiliation.

The ultimate goal, said Castriotta, is to create flexible, high-performance perovskite solar cells that achieve high efficiencies under regular sunlight and lower light conditions and to surpass the current best performance in this technology.

“The potential here is very clear,” said Castriotta. “Perovskite in just 12 years has already reached the same efficiency as silicon.”

Luigi Castriotta is working in the Huang Group to make perovskite solar modules more efficient and lead-free.