Mixed-Dimensional In-Plane Heterostructures from 1D Mo₆ Te₆ and 2D MoTe₂ Synthesized by Te-Flux-Controlled Chemical...

Mixed-dimensional van der Waals heterostructures are scientifically important and practically useful because of their interesting exotic properties resulting from their novel hybrid structures. This study reports the composition- and phase-selective fabrication of low-dimensional molybdenum/tellurium (Mo/Te) compounds and the direct synthesis of mixed-dimensional in-plane 1D-2D Mo₆ Te₆ -MoTe₂ heterostructures. The composition and phase of the Mo/Te compounds are controlled by changing the Te atomic flux that is adjusted by the Te temperature. Metallic 1D Mo₆ Te₆ wires with an intrinsic 1D structure with a diameter of 3-8 nm and length of 100-300 nm are synthesized to form wire networks under low Te flux conditions, whereas the semiconducting few-layer 2H MoTe₂ films preferentially oriented along the <0001> direction are obtained under high Te flux. Under medium Te flux, the mixed-dimensional in-plane 1D-2D Mo₆ Te₆ -MoTe₂ heterostructures are synthesized in which the semiconducting few-layer 2H MoTe₂ circular domains are edge-contacted by the metallic 1D Mo₆ Te₆ wire networks. Furthermore, the present Te-flux-controlled method reveals that the 1D Mo₆ Te₆ networks change to few-layer MoTe₂ films as the Te flux increases. The in-plane 1D-2D Mo₆ Te₆ -MoTe₂ heterostructures synthesized by this method can be considered as advanced edge-contacted 2D semiconductors for high-performance 2D electronics.