- Research team led by Professors Moonsup Han and Youngjun Chang, Department of Physics, University of Seoul

- Simultaneous switching and memory functionality with aluminum oxynitride overlayers

- Room-temperature processing & simple device structure: To open possibilities for next-generation low-power, high-speed information processing devices

Summary

A research team led by Professors Moonsup Han and Youngjun Chang in the Department of Physics at the University of Seoul has developed a novel field-effect transistor (FET) by integrating a two-dimensional semiconductor, molybdenum disulfide (MoS2), with an aluminum oxynitride (AlOxNy) overlayer. The device simultaneously achieves switching and memory functionalities, and its simple structure with room-temperature fabrication makes it suitable for large-area and flexible electronics.

The team further revealed that the out-of-plane lattice vibrations (phonons) of MoS2 enhance the charge-trapping mechanism at the MoS2/AlOxNy interface, thereby improving memory performance. These findings highlight the potential of the device as a neuromorphic component for future information-processing systems.

Details

The University of Seoul research team has developed a new material–device structure that shows strong promise for next-generation neuromorphic computing based on two-dimensional semiconductors. Fabricated through a simple room-temperature process, the device combines both transistor and memory operations in a single structure, offering a pathway to ultra-low-power, high-speed information processing.

For nearly 80 years, the von Neumann computing architecture—in which the processor and memory are physically separated—has served as the standard. However, as data scales grow, this separation causes transmission bottlenecks. The limitations become especially apparent in artificial intelligence and big data environments. As a result, neuromorphic computing, which integrates processing and memory functions in a manner analogous to the human brain, has emerged as a leading candidate for future computing technologies.

In this work, the team deposited an AlOxNy overlayer on MoS2 at room temperature, realizing a new FET structure that integrates switching and hysteresis-based memory within the same device. The device is compatible with large-scale integrated circuits and flexible electronics. Importantly, the researchers clarified that phonons in the vertical lattice vibrations of MoS2 enhance charge-trapping at the MoS2/AlOxNy interface, which significantly improves memory characteristics. This mechanism demonstrates the feasibility of neuromorphic devices capable of simultaneously controlling switching and memory functions through thermally coupled responses.

This research was published online on August 13, 2025 in American Chemical Society’s ACS Applied Materials & Interfaces (SCI Q1) under the title “Phonon-Assisted Charge Trapping and Threshold Voltage Modulation in MoS2 FETs with AlOxNy Overlayers.”

This research was supported by Basic Research Programs (Basic, Advanced, and Group Researches) and University-based Priority Research Centers Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology of Korea.

▶ Sangwoo Nam (First author), Hanyeol Ahn (Co-author), Hyun Su Park (Co-author), Young Jun Chang (Co-author), Moonsup Han (Corresponding author)