Abstract:

　　Two-dimensional layered electrides have attracted significant attention as a new class of 2D materials owing to the presence of unusual anionic electrons (AEs). The electride layers are more strongly bound by ionic interactions involving AEs compared with van der Waals layers, which is also critical to the physical and chemical properties of the materials. However, to date, the role of interlayer ionic coupling in determining the properties of 2D electrides has been largely unexplored. In this talk, we introduce our first-principles study of the effect of interlayer ionic couplings associated with AEs on the electronic properties of various existing and proposed layered electrides. A higher density of AEs in the 2D layered spacing leads to stronger localization and interlayer coupling strength, which induces a Stoner-type magnetic instability. In-plane strain can dramatically modify the configuration of AEs, thereby enabling strain engineering of 2D materials. Strikingly, the work function and interlayer binding energy of the layered electrides are distinctly related, which is in stark contrast to those of van der Waals materials.

Biosketch:

　　Jin-Ho Choi is currently Professor of College of Energy, Soochow University. He earned his PhD in theoretical condensed matter physics from Hanyang University in 2011, working with Prof. Jun-Hyung Cho. In his thesis work he studied the self-assembly mechanisms of one-dimensional molecular lines on semiconductor surfaces. After completing his PhD, he joined Prof. Zhenyu Zhang’s group at University of Science and Technology of China, where he studied the electronic properties of 2D or energy-related materials for 3 years as a postdoc. He then worked at Dongguk University and Pusan National University before he joined Soochow University in 2017. Dr. Choi is now focusing on 2D materials for energy applications. He has published 33 SCI papers.