US Patent Number
The present invention provides integrated nanostructures comprising a single-crystalline matrix of a material A containing aligned, single-crystalline nanowires of a material B, with well-defined crystallographic interfaces are disclosed. The nanocomposite is fabricated by utilizing metal nanodroplets in two subsequent catalytic steps: solid-liquid-vapor etching, followed by vapor-liquid-solid growth. The first etching step produces pores, or “negative nanowires” within a single-crystalline matrix, which share a unique crystallographic direction, and are therefore aligned with respect to one another. Further, since they are contained within a single, crystalline, matrix, their size and spacing can be controlled by their interacting strain fields, and the array is easily manipulated as a single entity—addressing a great challenge to the integration of freestanding nanowires into functional materials. In the second, growth, step, the same metal nanoparticles are used to fill the pores with single-crystalline nanowires, which similarly to the negative nanowires have unique growth directions, and well-defined sizes and spacings. The two parts of this composite behave synergistically, since this nanowire-filled matrix contains a dense array of well-defined crystallographic interfaces, in which both the matrix and nanowire materials convey functionality to the material. The material of either one of these components may be chosen from a vast library of any material able to form a eutectic alloy with the metal in question, including but not limited to every material thus far grown in nanowire form using the ubiquitous vapor-liquid-solid approach. This has profound implications for the fabrication of any material intended to contain a functional interface, since high interfacial areas and high quality interfacial structure should be expected. Technologies to which this simple approach could be applied include but are not limited to p-n junctions of solar cells, battery electrode arrays, multiferroic materials, and plasmonic materials.
University of Kentucky Research Foundation, Lexington, KY (US)
Guiton, Beth S. and Yu, Lei, "Synthesis of Metal Oxide Surfaces and Interfaces with Crystallographic Control Using Solid-Liquid-Vapor Etching and Vapor-Liquid-Solid Growth" (2019). Chemistry Faculty Patents. 40.