Orientation domain dispersions in wafer scale epitaxial monolayer WSe2 on sapphire

Monolayer WSe2, a 2D transition metal dichalcogenide (TMDCs), has been demonstrated as good candidate for potential applications in optoelectronics. It is imperative to know the crystalline quality of WSe2 over wafer scale prior its applications. Azimuthal reflection high-energy electron diffraction (ARHEED) be powerful technique measure symmetry, lattice constants, and in-plane orientation domain dispersion wafer-scale, continuous monolayer epitaxially grown by organic chemical vapor deposition on c-plane sapphire substrate. The constructed reciprocal map from ARHEED reveals few degrees’ domains due step meandering/bunching/mosaic Minor 30° are also observed. methodology can applied study other TMDCs epitaxial monolayers, graphene, confined atomically thin hetero-epitaxial metals.