3/24/2026 Jeni Bushman
Researchers have created the first artificially generated charged domain wall in a 2D ferroelectric material, by stacking two ultrathin layers of indium selenide crystal with opposing electrical polarizations to produce a highly conductive interface. Led by associate professor Arend van der Zande and graduate student Shahriar Muhammad Nahid, the work opens a new class of ferroelectric material interfaces with promising applications in neuromorphic computing and reconfigurable electronics.
Written by Jeni Bushman
Researchers from The Grainger College of Engineering have presented the first example of an artificially made charged domain wall in a 2D ferroelectric material.
In a first for the field, materials scientists from The Grainger College of Engineering at the University of Illinois Urbana-Champaign have interfaced two materials to artificially generate a highly conductive ferroelectric charged domain wall. Led by associate professor of materials science and engineering Arend van der Zande and graduate student Shahriar Muhammad Nahid (now a postdoc at Stanford) and published in Advanced Materials, their approach highlights the versatility of charged domain walls in 2D materials and may be used in the future development of neuromorphic devices and reconfigurable electronics.
2D materials are valued for their utility in molecular-scale systems, which are used to create new kinds of memory and molecular electronic architectures. While most materials must be grown naturally layer by layer, 2D materials can be stacked like building blocks to create arbitrary structures. One emerging 2D material of interest is indium selenide (α-In2Se3), a layered semiconductor that is also ferroelectric. Ferroelectric materials exhibit spontaneous and mutable electric polarization—something that piqued the interest of van der Zande and Pinshane Huang, professor of materials science and engineering.
While examining 2D ferroelectric materials with electron microscopy, Huang and graduate student Edmund Han noticed that charged domain walls—the interface where two electrically opposite regions meet inside a material—appeared spontaneously in natural crystals. Charged domain walls (CDW) are valuable in materials science because of their instability and reconfigurability. This observation inspired the Illinois Grainger engineers to intentionally create their own CDWs from scratch.
“We looked back at the history of ferroelectrics, and it turns out that charge domain walls are something that’s been known for decades in conventional ferroelectrics made from large crystals or thin films,” van der Zande said. “It was an ‘aha’ moment—these things we’ve known about can exist, but nobody had ever thought about how they would exist in 2D materials or what they could do.”
Nahid began by carefully stacking two ultrathin layers of indium selenide crystal, whose polarizations had been fixed in opposite directions. When both layers were electrically connected to their shared interface, their opposing polarities generated a large buildup of electrical charge, which pulled mobile electrons inside and transformed the interface into a highly conductive path. The result? A controlled, accessible conducting channel with resistance orders of magnitude lower than previous structures, functioned at room temperature and could be used as a transistor by tuning the density of states.
The Illinois researchers’ approach may be used to advance the development of neuromorphic devices, which mimic brain cells in their ability to change and adapt. Unlike other systems constrained by either low conductivity or poor control, CDWs in 2D ferroelectric materials exhibit both high conductivity and high controllability. To capitalize on this potential, van der Zande and his students are working towards their next goals: making memtransistors and evaluating their performance as neuromorphic computing elements, and creating CDWs in additional systems with mismatched polarizations.
“We’ve essentially opened up an entire new class of ferroelectric material interfaces that never existed before,” van der Zande said. “Now we’re trying to integrate different combinations of ferroelectrics. We could put a ferroelectric with very low polarizability onto a ferroelectric with high polarizability, which is usually impossible. We could switch the polarization of one layer and leave the other layer set, and we could turn these wires on and off and make them conducting or insulating and in a non-volatile way. Or maybe we could switch between multiple states and that could become a new form of multi-state memory. We are effectively creating a completely new strategy to address this very old problem, and now we can explore the different avenues that this new class offers.”
Other contributors to the project included Haiyue Dong and physics professor Nadya Mason, who performed low temperature electrical transport, and Gillian Nolan, who performed electron microscopy imaging.
Illinois Grainger Engineering Affiliations
Arend van der Zande is an Illinois Grainger Engineering associate professor in the Department of Materials Science and Engineering and the Department of Mechanical Science and Engineering. He is also affiliated with the Department of Electrical and Computer Engineering, the Holonyak Micro and Nanotechnology Lab, and the Materials Research Laboratory.
Pinshane Huang is an Illinois Grainger Engineering professor and Racheff Faculty Scholar in the Department of Materials Science and Engineering. She is affiliated with the Materials Research Laboratory.