Scalable synthesis of millimeter-long single crystal TaNiSe Van der Waals nanowires.

One-dimensional (1D) van der Waals (vdW) nanowires, formed from molecular chains bonded through weak interactions, represent a significant departure from traditional nanowires by offering the potential to miniaturize functional devices to the molecular scale while maintaining crystallinity, a feature attributable to their exfoliable nature and chemically inert surfaces. However, the lack of efficient synthesis methods has hindered the exploration of their intrinsic properties and potential applications. The production of vdW nanowires has predominantly relied on the exfoliation of bulk crystals, leaving their direct synthesis largely unexplored. In this work, we introduce a novel solid-state growth technique that facilitates the high-yield and scalable fabrication of single-crystal TaNiSe (TNS) nanowires, achieving a consistent thickness of 100 nm and lengths extending to several millimeters. We further demonstrate a few centimeter scale alignments of as-grown nanowires and show that these nanowires can be easily dry exfoliated to produce several nanometer-thick, air-stable nanowires. Employing density functional theory, we investigate the bonding characteristics within these nanowires, identifying a highly anisotropic bonding density that significantly contributes to their facile exfoliation. Moreover, the development of Schottky device arrays on individual TNS nanowires and subsequent electrical transport measurements affirm the uniform Schottky contact properties along their entire length, characterized by a barrier height of approximately 0.39 eV. The successful synthesis of structurally and electronically uniform, ultralong TNS nanowires may open a new avenue in developing integrated molecular electronics and sensors using 1D vdW materials.