Journal Article 2D materials van der Waals heterostructures chemical vapor deposition density functional theory scanning transmission electron microscopy 2D homojunctions Au‐template‐assisted mechanical exfoliation Co doping MoS2 MoTe2 WTe2 anisotropy dislocations dry‐transfer techniques electrocatalysis epitaxial growth few layer MoSe2 grain boundaries graphene hydrogen evolution reaction hydrogenated graphene interface vibrations interlayer excitons interlayer shear mode local atomic vibrations logic gates logic rectifiers millimeter-scale moiré superlattices