Synthesis of WTe₂ Nanowires with Increased Electron Scattering.

Abstract

Tungsten ditelluride (WTe₂) has many interesting properties such as its extremely large nonsaturating magnetoresistance and quantum spin Hall state in the monolayer limit. The anisotropic crystal structure of WTe₂ can allow for isolation of particular crystal directions to study the predicted Weyl states or crystal-symmetry-dependent magnetoresistance when studied at limited dimensions. In particular, the recent demonstration of superconductivity in WTe₂ monolayer suggests that realizing nanowire geometry for WTe₂ may be important to investigate potential Majorana zero modes predicted in one-dimensional topological superconductors. In this work, we demonstrate a large-yield, low-temperature synthesis of WTe₂ nanowires, an approximate one-dimensional system, by converting WO₃ nanowires via tellurization. The nanowires are single crystalline and have a higher resistivity than WTe₂ exfoliated flakes with similar thickness. The increased resistivity is attributed to increased scattering from imperfect surfaces and higher surface-to-volume ratios of the WTe₂ nanowires. We demonstrate that the synthesis method is generalizable to other transition-metal dichalcogenides, laying the foundation for further study of this class of materials in the one-dimensional limit.