Salt-assisted vapor-liquid-solid growth of one-dimensional van der Waals materials.

We introduce the method of salt-assisted vapor-liquid-solid (VLS) growth to synthesize one-dimensional (1D) nanostructures of trichalcogenide van der Waals (vdW) materials, exemplified by niobium trisulfide (NbS3 ). The method uses a unique catalyst consisting of an alloy of Au and an alkali metal halide (NaCl) to enable rapid and directional growth. We demonstrate high yields of two types of NbS3 1D nanostructures, nanowires and nanoribbons, each with sub-ten nanometer diameter, tens of micrometers length, and distinct 1D morphology and growth orientation. We present strategies to control the location, size, and morphology of growth, and extend the growth method to synthesize other transition metal trichalcogenides, NbSe3 and TiS3 , as nanowires. Finally, we describe the role of the Au-NaCl alloy catalyst in guiding VLS synthesis and discuss the growth mechanism based on the relationships we measure between structure (growth orientation, morphology and dimensions) and growth conditions (catalyst volume and growth time). These results introduce opportunities to expand the library of emerging 1D vdW materials to make use of their unique properties through controlled growth at nanoscale dimensions. This article is protected by copyright. All rights reserved.