Title: Investigation of crystal anisotropy of few-layer semimetallic T’-MoTe2 by angle-resolved polarized Raman spectroscopy
Speaker: Junyong Wang
Abstract Details: The distorted octahedral T’ phase MoTe2 has received tremendous interests recently due to its novel electronic structures and anisotropic charge transport properties. Taking advantage of its reduced in-plane symmetry, we find an easy and non-destructive method for determining the crystal orientation for thin layer T’-MoTe2 flakes by Raman spectroscopy. The Bg and Ag modes show blue-shift and red-shift with increasing thickness, respectively, due to the anisotropic surface effect. By exploring the anisotropic Raman response of thin layer T’-MoTe2 based on angle-resolved polarized Raman spectroscopy, we found four types of angular dependent behaviors, which are further analyzed from the group theory. The intensity of Ag mode at around 162 cm-1 reaches its maximum when the polarized excitation laser is parallel to the metal-metal bonds direction in the parallel configuration. This study paves the way for investigation about correlation between physical and structural properties of thin film T’-MoTe2.