UMBC researchers pioneer method to discover new 2D materials for advanced electronics

Finding new materials with useful properties is a primary goal for materials scientists, and it’s central to improving technology. One exciting area of current research is 2D materials—super-thin substances made of just a few layers of atoms, which could power the next generation of electronic devices. In a new study, researchers at the University of Maryland Baltimore County (UMBC) developed a new way to predict 2D materials that might transform electronics. The results were published in Chemistry of Materials on July 7.

Picture a sheet of paper so thin that it’s only a few atoms thick, and that’s what 2D materials are like. One might think they would be fragile—but these materials can actually be incredibly strong or conduct electricity in unique ways. They’re held together by weak forces called van der Waals bonds, which allow materials to slightly deform without breaking under stress. Stacked layers of these 2D materials can slide past each other, further reducing brittleness. 

The research team, led by Peng Yan, a UMBC Ph.D. candidate in chemistry, and Joseph Bennett, assistant professor of chemistry and biochemistry at UMBC, focused on a type of 2D material called van der Waals layered phosphochalcogenides. Some of these materials are ferroelectric, meaning they can hold an electric charge in a particular direction, and then the direction can be reversed on command—sort of like tiny, reversible batteries. Some ferroelectric materials are also magnetic, behaving similarly when a magnetic field is applied. That combination makes them ideal for advanced electronics like memory devices and sensors.

“There's only two known 2D van der Waals ferroelectric materials with this type of structure,” Bennett said, “so we were asking ourselves, where might others be hiding?” The new publication is their answer to that question.

A treasure map to new materials

The researchers used a mix of data mining, computer modeling, and structural analysis (because only materials with certain shapes are conducive to use in electronics) to ferret out new material candidates. 

“We developed a set of chemical design rules to predict these materials, which could significantly accelerate the discovery of new functional materials,” Yan, the study’s first author, said.

Joshua Birenzvige, an undergraduate working with Bennett, played a key role by developing a Python script that helped sort the potential materials based on their properties, speeding up the team’s progress. Mona Layegh, a Ph.D. candidate in Bennett’s group, is also a co-author on the new paper.

The researchers began by digging into the Inorganic Crystal Structure Database, a huge collection of known crystal structures. Then they used quantum structural diagrams—which map materials on a chart according to how they relate to each other, determined by their atomic traits—to find areas within the diagrams where promising new materials might be hiding.

“By analyzing basic parameters like differences in electronegativity and radius, we were able to separate materials that have the properties we want from those that don’t,” Bennett explained. Electronegativity measures how strongly an atom attracts electrons, and an atom’s radius is the distance from its center to the outer edge of its electron cloud.

“These quantum structural diagrams act like a treasure map,” Bennett said, “guiding us to regions of chemical space where new, stable 2D materials are likely to exist.”

Their results indicated 83 potential new materials that could be made and used in the tech industry, potentially increasing the number of known ferroelectric materials by an incredible margin. 

From the computer to the lab bench

After the computer-based analysis, the team took their work a step further. The UMBC researchers collaborated with Ryan Stadel, Peter Zavalij, and Efrain Rodriguez at the University of Maryland, College Park (UMD), who made and tested some of the predicted materials in the lab. Their work proved the UMBC predictions could be used to guide experiments with the novel materials.

“Being able to predict which compositions are likely to form stable, functional materials gives us a huge head start in the lab,” Bennett said. “It’s like having a recipe book for materials that haven’t been made yet, which saves time and resources.”

These new materials could shine in real-world uses, substantially advancing the electronics industry. For example, they could help build memory devices that can store data after power is shut off, tiny sensors that detect minute amounts of particular substances, or low-power components that make your phone battery last longer. These properties are in high demand across the tech industry and the U.S. government—this work was funded by a substantial grant from the Defense Threat Reduction Agency.

An exciting future of discovery

“I’m excited because the work demonstrates a successful data-guided approach to discovering novel 2D materials with promising functional properties, potentially accelerating the design of next-generation electronic materials,” Yan said.

Next up, the team will use a complex computer simulation, called high-throughput density functional theory modeling, to explore these 83 materials in more depth. They’ll check their ferroic traits and how easily they can be made. Plus, they’ll continue their collaboration with UMD to synthesize and study the materials in the lab, aiming to confirm their special properties and tweak them for specific applications.

The research is a major step forward, paving the way for materials that could change how engineers build electronics—from sensors for the military to longer-lasting laptops and tablets for students on the go.