Absorption dichroism of monolayer 1T '-MoTe2 in visible range

Abstract

Among various transition metal dichalcogenides, MoTe2 has drawn attention due to its capability of robust phase engineering between semiconducting (2H) and semi-metallic distorted octahedral (1T') phase. In particular, 1T'-MoTe2 has been predicted to have intriguing physics such as quantum spin Hall. insulator, large magnetoresistance, and superconductivity. Recent progress showed weak antilocalization behavior in 1T'-MoTe2 which is the one of representative characteristics in topological insulator. Here, we grow centimeter-scale monolayer 1T'-MoTe2 on SiO2/Si substrate via chemical vapordeposition and demonstrate dichroism in visible range. Ribbon-like 1T'-MoTe2 flakes were initially nucleated randomly on SiO2 substrate and at a later stage merged to form a continuous monolayer film over the entire substrate. Each flake revealed one dimensional Mo-Mo dimerization feature and anisotropic absorption behavior in visible range (400-600 nm). This allowed us to detect the grain boundary due to stark contrast difference among flakes in different orientations.