Emergent Ferroelectricity in (Ultra)wide-Bandgap Nitrates
Speaker
Zetian Mi
Professor of Electrical Engineering and Computer Science, University of Michigan
About This Talk
Ferroelectricity has historically been associated primarily with complex oxides, while III-nitride semiconductors are best known for their exceptional chemical stability, large bandgaps, and strong spontaneous and piezoelectric polarization. Recent discoveries have revealed an unexpected connection between these two material classes: incorporation of group-IIIB elements such as Sc and Y can transform conventional III-nitrides into robust ferroelectrics while simultaneously producing dramatic enhancements in their dielectric, piezoelectric, electronic, and optical responses.
In this presentation, Zetian Mi of the University of Michigan will discuss the materials physics underlying this emerging class of ferroelectric semiconductors. He will first describe how alloying reshapes the structural and energetic landscape of wurtzite nitrides, enabling giant piezoelectric responses and polarization reversal. He will then discuss ferroelectric switching, polarization dynamics, and the nucleation and motion of domain walls, including unusual charged horizontal domain walls and their interaction with electronic charge. These phenomena reveal a rich coupling among crystal structure, polarization, defects, carriers, and interfaces that is distinct from that of conventional oxide ferroelectrics.
Finally, Mi will discuss the fundamental materials challenges that currently limit nitride ferroelectrics, including coercive fields, leakage, defects, interfaces, and polarization control, as well as emerging strategies to overcome them. He will highlight how advances in materials synthesis and heterostructure engineering may enable new opportunities spanning electronics, photonics, acoustics, and programmable semiconductor devices, while opening broader questions about ferroelectricity in wide- and ultrawide-bandgap materials.
About the Speaker
Zetian Mi is a professor in the Department of Electrical Engineering and Computer Science and the Pallab K. Bhattacharya Collegiate Professor of Engineering at the University of Michigan, Ann Arbor. His research focuses on wide- and ultrawide-bandgap semiconductors and their applications in microelectronics, photonics, and artificial photosynthesis. He is a recipient of the IEEE Photonics Society Engineering Achievement Award (2026), the Optica Nick Holonyak, Jr. Award (2025), the AVS Nanotechnology Recognition Award (2025), the ISCS Quantum Devices Award (2024), and the W. M. Keck Foundation Science and Engineering Award (2020). He is a Fellow of IEEE, APS, Optica, and SPIE, and a co-founder of NS Nanotech Inc. and NX Fuels Inc.