The Study of Atmospheric Pressure CVD Growth Process of Mo_xW_1-xTe₂ Nanobelts for Tuneable Chemical Composition

Transition metal dichalcogenides nanomaterials with topological semimetallic phase (MoTe₂, WTe₂ and Mo_xW_1-xTe₂) are expected to realize no-consumption electronic transportation due to its Dirac point. Especially, the various structure existence in Mo_xW_1-xTe₂, like hexagonal (2H), monoclinic (1T') and othorombic (T_d), provides opportunities for phase engineering, which is beneficial for future novel electronic and spintronic devices. Plenty works have focused on the synthesis of MoTe₂, WTe₂ and Mo_xW_1-xTe₂ nanomaterials. Unfortunately, the understanding of the growth process of Mo_xW_1-xTe₂ nanomaterials is still absent and the exact control of the atomic ratio between Mo and W in Mo_xW_1-xTe₂ nanomaterials is still a huge task up to now. Here, we study the growth process of Mo_xW_1-xTe₂ nanomaterials by the growing of binary MoTe₂ and WTe₂ nanomaterials. Through detailed structural and compositional characterization, same growth mode, crystallography, and morphology have been observed among MoTe₂, WTe₂ and Mo_xW_1-xTe₂ nanomaterials. Through analysis, we suggest that the heating temperature of Mo and W precursors during the CVD process is the key parameters to achieve the tuneable chemical composition of Mo_xW_1-xTe₂ nanomaterials. This study dissected the growth process of Mo_xW_1-xTe₂ nanomaterials and provided a possible method to control the chemical composition of Mo_xW_1-xTe₂ nanomaterials by APCVD, which is beneficial to realize the phase engineering in Mo-W-Te system and also for future topological application. (paper)