As a materials scientist and director of the Two-Dimensional Crystal Consortium (2DCC), Joan Redwing often has to look far into the future to see the fruits of her labor.
Decades of research and the painstaking process of creating flawless materials—layer by layer—precede the application of the material in our everyday devices. But to see the team and the facilities required to get to that point, she doesn’t have to look so far.
The 2DCC is a National Science Foundation (NSF)-funded Materials Innovation Platform national user facility, which is designed to pave the way for the implementation of next-generation materials while simultaneously training experts to work in the same realm. The facility, which was launched five years ago and recently received $20.1 million in continued funding from the NSF, is one in a few globally with such capabilities. In terms of its facilities, expertise and results, Redwing said, it’s alone at the top.
“We’ve established the 2DCC as the premier facility in the United States for the synthesis of 2-D materials,” said Redwing, whose disciplines merge materials, chemical, and electrical engineering. “There’s really nothing similar to our facility in the United States and maybe the world. We’re definitely recognized as leaders in the synthesis of these materials.”
What are 2-D materials?
The materials we think of—a piece of plastic, the head of a hammer, a soda can—are so-called bulk materials because the material has three dimensions. For 2-D materials, which consist of a single layer of crystals, the material is a single layer of film.
What’s unique about 2-D materials is that its properties often change dramatically. For example, silver is one of the most conductive materials in bulk form, where the electric current can flow in one or more directions. But as a 2-D film, it’s a semiconductor, where the electric current has connectivity between a conductor and an insulator, allowing control of the current. It’s capable of turning electric impulses on and off just like the silicon chips found in everything from your automobile to your cell phone.
We’ve known about the powerful properties of materials that in 2-D form have a strong bond in just two directions—think of a single sheet of paper laid flat—but creating perfect layers of these materials, until recently, has proved difficult, Redwing said.
2DCC’s role is simplifying that process while using materials creation methods that are already prevalent in American tech industries and can easily be scaled up. Boosting American manufacturing and lessening the nation’s global reliance on high-tech materials is one of the goals outlined by the NSF.
The role of 2DCC
From materials theory and computation—where supercomputers are used to help understand the properties of a material before it’s even created—to synthesis, or creation, to the characterization, 2DCC has experts.
Synthesis is one area that stands out. While many facilities are able to create flakes of 2-D materials, Penn State is creating large-scale wafers similar to what’s used commercially via a process known as chemical vapor deposition. In high-end electronics manufacturing, these wafers serve as the medium for which tiny slices of a material are harvested. The creation of these materials is also driving research at Penn State and beyond. The facility spends about half its resources creating films and crystals for researchers globally.
Because few electronics are made with one material, the next step will be creating complex layers of 2-D materials destined for new and hyperfast electronics. This could have a huge impact in areas of supercomputing, quantum computing, and high-tech electronics. And, because items like modern-day cars are employing the same technologies as a smartphone, these materials are becoming more commonplace.
The pace of discovery
The fevered pace of discovery is something that excites Joshua Robinson, a 2-D materials expert and director of user programs at 2DCC. Robinson said the globalization of knowledge has hastened the pace of research, and with that comes discovery.
He said the pace of published research is a double-edged sword: So much valuable research brings both knowledge and noise. That’s why having a collaborative group within 2DCC reaps rewards.
“There is this beacon at the NSF that people migrate towards. As opposed to all of us individually publishing papers, now we’re doing it collectively as a team,” Robinson said. “And that elevates the impact of our work, especially with the NSF recognition that Penn State is a special place that has unparalleled material science and research capabilities.”
Robinson’s group pioneered a method for creating graphene—that’s the 2-D form of graphite—that can be used in anything from protecting metals from quickly oxidizing in demanding applications to extending the life of your car tires by reducing heat caused by road friction.
Robinson said the facility simultaneously advances research while advancing researchers. One program, the Resident Visitor Scholar Program, invites graduate students and early-career researchers to train at the facility.
“This really is about expanding our knowledge of two-dimensional crystals while advancing the education of next-generation scientists,” Robinson said.
A generation to lead the way
When 2DCC leaders talk about training the next generation of experts, they mean people like Nick Trainor, who came to Penn State in 2019 to earn his Ph.D. in materials science and engineering. Trainor earned the NSF Graduate Research Fellowship in 2020.
Trainor said the facilities, faculty, and training-centric approach drew him to the University. He’s not certain if he’ll enter academia or the private sector after graduating but he knows his skills in both research and training—he helps shadow visiting graduate students at the 2DCC facility—will help him earn a career in either.
As an undergraduate at Drexel University, Trainor worked in 2-D materials. For his doctoral thesis at Penn State, he’s investigating heterostructures. These structures, which combine several 2-D materials to achieve more complex functions, will be the next big breakthrough in the realm because most electronic devices require it.
Trainor sees these heterostructures as not some big pipe dream for researchers but rather something attainable in his career. In fact, that’s one reason he chose to work in 2DCC. The techniques are already prevalent.
“Chemical vapor deposition is a process where we feed compounds into a reactor as gases and those compounds react and then deposit as a film,” Trainor said. “This technique is actually very common. It’s used in making LEDs and lasers. What we’re doing here in principle can readily be transferred out to real world manufacturing.”
As the future of manufacturing plays out, Redwing hopes to continue to guide Penn State on a path that’s leading the way in the creation of all forms of materials, not just 2-D materials. Doing that, she said, will require more faculty, funding, and facilities.
“I would like to see Penn State become the premier institution in the United States for material synthesis overall,” Redwing said. “I’m hoping a lot of the equipment that we’ve put in place for 2-D materials can also help to grow Penn State’s strength in semiconductors and related electronic materials. My ultimate goal is to further build our strengths in material synthesis.”