Controlled Synthesis of MoxW1-xTe2 Atomic Layers with Emergent Quantum States

Recently, new states of matter like superconducting or topological quantum states were found in transition metal dichalcogenides (TMDs) and manifested themselves in a series of exotic physical behaviors. Such phenomena have been demonstrated to exist in a series of transition metal tellurides including MoTe2, WTe2, and alloyed MoxW1-xTe2. However, the behaviors in the alloy system have been rarely addressed due to their difficulty in obtaining atomic layers with controlled composition, albeit the alloy offers a great platform to tune the quantum states. Here, we report a facile CVD method to synthesize the MoxW1-xTe2 with controllable thickness and chemical composition ratios. The atomic structure of a monolayer MoxW1-xTe2 alloy was experimentally confirmed by scanning transmission electron microscopy. Importantly, two different transport behaviors including superconducting and Weyl semimetal states were observed in Mo-rich Mo0.8W0.2Te2 and W-rich Mo0.2W0.8Te2 samples, respectively. Our results show that the electrical properties of MoxW1-xTe2 can be tuned by controlling the chemical composition, demonstrating our controllable CVD growth method is an efficient strategy to manipulate the physical properties of TMDCs. Meanwhile, it provides a perspective on further comprehension and sheds light on the design of devices with topological multicomponent TMDC materials.

Automated summary

Recent studies have discovered new states of matter in transition metal dichalcogenides (TMDs) with exotic physical behaviors, such as superconductivity and topological quantum states. A facile CVD method was developed to synthesize MoxW1-xTe2 alloy with controllable thickness and chemical composition ratios, showing different transport behaviors like superconductivity and Weyl semimetal states in Mo-rich and W-rich samples. This controllable growth method proves to be an efficient strategy in manipulating electrical properties of TMDCs and provides insights for the design of devices using topological multicomponent TMDC materials.