Structural Study Of DVT Grown Mo W Se (x =0, 0.25, 1)X 1-X 2 Single Crystals

Abstract

Transition metal dichalcogenides(TMDCs) MX (M=Mo,W; X= S or Se) are semiconducting compounds exhibiting layered 2 structure. The single crystals of MoW Se (x=0, 0.25, 1) belonging to this family have been grown by direct vapour transport x 1-x 2 (DVT) technique. The chemical composition, basic structure and morphology of the as-grown crystals have been studied by energy dispersive analysis of X-rays (EDAX), X-ray Diffraction (XRD) and optical microscopy. EDAX study indicates that the compounds are nearly stoichiometric. The optical microscopy and XRD results show that the crystals grow predominantly as 2H-hexagonal polytypes. However, MoSe and Mo W Se seem to contain a little proportion of 3R- rhombohedralpolytypes.