Image credit: Pawel-D-browski on Pixabay.
As electronic devices handle ever-increasing volumes of data, reducing the energy needed to store and process information has become an important challenge. One promising approach is to combine atomically thin semiconductors with ferroelectric materials, enabling devices to retain electrical states without continuous power. In a lecture delivered today as part of the QAMSS lecture series, Prof. Seunguk Song of Sungkyunkwan University (SKKU), Korea, explored how advances in these materials could pave the way for more energy-efficient electronics that integrate memory and logic.
Ferroelectrics give layered materials a lasting memory
Ferroelectric materials retain their electrical polarisation after an applied voltage is removed. When placed alongside a two-dimensional (2D) semiconductor, this creates a switchable electric field that can control the semiconductor's electrical properties without continuous power.
Prof. Song explained that a ferroelectric effectively “writes a doping state into the layered material and holds it there without standby power.” He continued, “Crucially, the polarisation can be adjusted to intermediate levels, allowing a transistor to store multiple states rather than just the conventional on and off states.”
His group has used ferroelectric nitrides and oxides, including aluminium scandium nitride (AlScN) and hafnium zirconium oxide (Hf₀.₅Zr₀.₅O₂), to develop 2D transistors and memories that retain their programmed states. As Prof. Song put it, this “turns an ordinary switch into a combined memory and logic element.”
Such devices could help reduce the energy consumed when data moves between separate memory and processing chips. Prof. Song identified non-volatile memories, memory-embedded logic and in-memory computing as promising applications, where information can be stored and processed within the same device.
Overcoming barriers to wafer-scale 2D electronics
Realising this potential, however, requires more than demonstrating ferroelectric switching. “The main challenges sit at the materials level: 2D films must be grown uniformly at the wafer scale, contact resistance must stay low enough not to mask the ferroelectric switching, and the ferroelectric–semiconductor interface must survive repeated cycling without trapping charge”, Prof. Song explained.
His group is addressing these challenges through metal-organic chemical vapour deposition (MOCVD), a technique for growing 2D chalcogenides with controlled composition and crystal structure. The research also explores semimetallic van der Waals contacts, which can reduce contact resistance and improve device performance.
As Prof. Song explained, “Our approach is to tackle these together”, combining uniform film growth, low-resistance contacts and ferroelectrics compatible with established semiconductor manufacturing processes.
A key challenge is ensuring that the interface between the ferroelectric and semiconductor survives repeated switching without trapping unwanted electrical charge. Solving these materials-level problems could help bring programmable, multi-state electronics closer to practical application.
Together, the advances point towards a future in which wafer-scale 2D material platforms support both memory and logic, potentially reducing energy consumption while expanding the functionality of electronic devices.
About the interviewee
Image credit: Courtesy of Seunguk Song (QS Lab, SKKU).
Prof. Seunguk Song, Sungkyunkwan University (SKKU), Korea
Seunguk Song is an assistant professor in the Department of Energy Science at Sungkyunkwan University (SKKU) and a team leader at the IBS Center for 2D Quantum Heterostructures, Korea. He received his PhD in materials science and engineering from UNIST (2021) for his work on the large-area synthesis of two-dimensional (2D) semiconductors, and was a postdoctoral researcher at the University of Pennsylvania (2021–2024), where he developed ferroelectric AlScN-gated 2D transistors and memories. His group at SKKU focuses on wafer-scale metal-organic chemical vapour deposition (MOCVD) of 2D chalcogenides, phase-selective growth of van der Waals contacts, non-volatile ferroelectric gating and quantum light sources in 2D materials. His work has been published in journals including Nature Electronics, Nature Communications and ACS Nano.
By Dr Karen Steward