[3Ia01-06] Two-Dimensional (2D) Materials

[3Ia03] First-principles study on two-dimensional materials of silicon/germanium

*Masaaki Araidai¹, Mai Itoh², Daiki Ishihara², Masashi Kurosawa², Akio Ohta³, Ai Yamakage⁴, Kenji Shiraishi¹ (1. Institute of Materials and Systems for Sustainability, Nagoya University, 2. Graduate School of Engineering, Nagoya University, 3. Department of Applied Physics, Fukuoka University, 4. Department of Physics, Nagoya University)

Two-dimensional crystals composed of silicon and germanium, silicene and germanene, have interesting properties, such as high carrier mobility, band-gap control and topological electronic states. However, it is difficult to fabricate the freestanding ones. In this presentation, we report on the hydrogen desorption characteristics of monolayer and multilayer hydrogenated silicene (silicane) and germanene (germanane) crystals. The calculations show a way to create free-standing silicene/germanene from monolayer silicane/ germanane. Silicene and germanene are equivalent to a single bilayer on (111) plane of the bulk structure without hydrogen termination, and it is well known that they exhibit topological electronic states. Then, what kind of electronic states do the ultra-thin crystals stacked in (111) direction have? In this presentation, I will also present the results on the electronic structures of the ultra-thin film crystals using the first-principles calculations.