Molybdenum ditellurides (MoTe2) have recently attracted attention owing to their excellent structurally tunable nature between 1T′(metallic)- and 2H(semiconducting)-phases; thus, the controllable fabrication and critical identification of MoTe2 are highly desired. Here, we semi-controllably synthesized 1T′- and 2H-MoTe2 crystals using the atmospheric pressure chemical vapor deposition (APCVD) technique and studied their grain-orientation dependency using polarization-sensitive optical microscopy, Raman scattering, and second-harmonic generation (SHG) microspectroscopy. The polycrystalline 1T′-MoTe2 phase with quasi-1D "Mo-Mo" zigzag chains showed anisotropic optical absorption, leading to a clear visualization of the lattice domains. On the other hand, 2H-MoTe2 lattice grains did not exhibit any discernible difference under polarized light illumination. The combined aforementioned microscopy techniques could be used as an easy-to-access and non-destructive tool for a quick and solid identification of intended lattice orientation development in industry-scale MoTe2 crystal manufacturing.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) funded by the Korean government (MSIT) (NRF-2015R1A3A2066337 and 2018R1A2A2A05019598).
© 2018 The Royal Society of Chemistry.
All Science Journal Classification (ASJC) codes
- Materials Science(all)