Synthesis of Single-Crystalline Tungsten Ditelluride (WTe2) Nanostructures Using Eutectic Metal Alloys

Abstract

Beyond graphene, group-VI transition metal dichalcogenides (TMDs) which is compound of transition metal and chalcogen have recently attracted much attention and mechanically exfoliated flakes of two-dimensional TMDs hold great promise due to their rich variety of properties. As a member of the TMDs family, tungsten ditelluride (WTe2), which has a stable distorted octahedral phase (1T’) among several polymorphs, are appealing because of their unique properties such as an unusual magnetoresistance and quantum spin Hall effect. In an effort to synthesize WTe2 nanostructures, researchers have tried to develop many growth techniques. Nonetheless, there remains considerable difficulty in obtaining high-quality WTe2 nanostructures due to a high equilibrium vapor pressure of tellurium at growth temperatures and a weak binding energy of W-Te than other chalcogens.

Here, we suggest a novel facile method to realize the synthesis of single-crystalline WTe2 nanostructures using eutectic metal alloys. In our work, we studied on the role of eutectic metal alloys and its behavior on synthesis parameters and more details will be presented. In addition, the as-synthesized WTe2 nanostructures can be easily transferred to different substrates and/or solutions as well as successfully formed on desired substrate without the needs for a further transfer process. The transfer-free formation of WTe2 nanostructures can be adopted to research the novel properties of WTe2 nanostructure without any degradation of the intrinsic characteristics. Moreover, feasibility of synthesis for MoTe2 nanostructure as a member of the layered TMDs family was evaluated through our methods. We expect that the emergence of new type of transition metal telluride nanostructures will create exciting prospects for further technical devices and applications in nano-electronics, catalysts and other fields.