1. Date / Time
- May 20, 2022
- 11:00 AM (KST)
2. Place / ZOOM (E6-2 #1323)
- Prof. Kwanpyo Kim (Department of Physics, Yonsei University)
4. Talk Title
- Exploration of new polymorphs in van der Waals crystals
- Crystals with layered structures have recently captured intense research interest. Each layer in these crystals is stacked together via relatively weak van der Waals interaction and can be isolated to be an atomic-thin layer. Various meta-stable stacking configurations can be realized in these systems, including twisted stacking configurations, which can be also exploited for tuning physical properties. Moreover, for some layered crystals, new intralayer structures can be also obtained by new synthetic methods. In this seminar, I will introduce my recent research effort to identify polymorphic configurations in existing layered crystals as well as develop new polymorphic configurations. For structural analysis of layered crystals at atomic resolution, atomic resolution transmission electron microscopy and other complementary techniques can be utilized. Various stacking configurations in layered crystals will be discussed. As an example of a new polymorphic configuration, we recently reported the synthesis of the first hexagonal polymorph, γ-GeSe, from the family of group IV-VI monochalcogenides. I will discuss the basic characteristics and expected physical properties of γ-GeSe.