Research Seminar of Prof.Tan Pinghengfrom Institute of Semiconductors, Chinese Academy of Sciences
Lecture Time: 10:30 on 19th October, 2018
Lecture Room: C501 of Science and Innovation Building
Lecture Title: Raman Spectroscopy Study of Two-Dimensional Materials and their Van der Waals Heterojunctions
Prof.Tan Pingheng
Institute of Semiconductors, Chinese Academy of Sciences
Abstract
Compared to conventional semiconductor heterostructures, van der Waals heterostructures (vdWHs) based on two-dimensional materials (2DMs) are readily fabricated by direct chemical-vapor-deposition growth or wet/dry transfer. Those vdWHs have ultraclean and atomically sharp interfaces, providing a versatile platform for studying interface-related properties. Also, the material choice of the components, layer thickness and interlayer twist angle q widely enrich the vdWHs and provide multiple degrees of freedom to engineer their optical and electronic properties. Raman spectroscopy is widely used to monitor the crystal quality, polytypism, doping, defects, strain, disorder, chemical modification, and relative orientation of 2DM flakes. In this talk, I will review the recent advances in the Raman spectroscopic study of two-dimensional materials, twisted bilayer two-dimensional materials and two-dimensional van der Waals heterostructures to quantitatively probe the interfacial coupling in the heterostructures and to map the phonon dispersions of the monolayer constituent in the twisted bilayer.