RIAM Member makes breakthrough discovery in structure and synthesis of 2D ferroelectrics

A research team led by Prof. ZHAO Jiong, Member of the Research Institute for Advanced Manufacturing (RIAM) and Associate Professor in the Department of Applied Physics of The Hong Kong Polytechnic University (PolyU), has made significant discoveries while investigating 2D ferroelectrics and 2D van der Waals materials. The team unveiled a pioneering approach for the large-scale synthesis of indium selenide (In₂Se₃), and provided new insights into the critical mechanisms that underlie the characteristics of 2D van der Waals materials and bilayer 2D materials.

In₂Se₃ is a promising 2D ferroelectric material, but the large-scale synthesis of 2D In₂Se₃ films with the desired phase is still lacking. The team used the transmission electron microscopy (TEM) technique to directly observe and analyse the ferroelectric domains, domain walls and other crucial features at the atomic level within the materials, and successfully synthesised 2D In₂Se₃ films with a pure phase. The findings were published in in Nature Nanotechnology.

Furthermore, the team’s work revealed the ultra-high plasticity of materials in 2D metal monochalcogenides such as InSe, and complex vortex patterns with tunable characteristics in twisted-bilayer molybdenum disulfide (MoS₂). The two findings have been published in Nature Materials and Science, respectively.

These scientific discoveries have facilitated significant technological advances in microelectronics, artificial intelligence and quantum information, and present promising prospects for diverse applications including high-density memory devices, energy conversion systems, sensing technologies and catalysis technologies.

The above studies were supported by PolyU’s Atomic Transmission Electron Microscopy Laboratory and the contributions of the research team: Prof. Daniel LAU Shu-ping, Chair Professor of Nanomaterials and Head of the PolyU Department of Applied Physics; Prof. YANG Ming, Assistant Professor in the PolyU Department of Applied Physics; and Prof. LY Thuc Hue, Associate Professor in the Department of Chemistry at City University of Hong Kong.