Optically oriented attachment of nanoscale metal-semiconductor heterostructures in organic solvents via photonic nanosoldering.
Nat Commun 2019;
10:4942. [PMID:
31666504 PMCID:
PMC6821866 DOI:
10.1038/s41467-019-12827-w]
[Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 09/06/2019] [Indexed: 11/17/2022] Open
Abstract
As devices approach the single-nanoparticle scale, the rational assembly of nanomaterial heterojunctions remains a persistent challenge. While optical traps can manipulate objects in three dimensions, to date, nanoscale materials have been trapped primarily in aqueous solvents or vacuum. Here, we demonstrate the use of optical traps to manipulate, align, and assemble metal-seeded nanowire building blocks in a range of organic solvents. Anisotropic radiation pressure generates an optical torque that orients each nanowire, and subsequent trapping of aligned nanowires enables deterministic fabrication of arbitrarily long heterostructures of periodically repeating bismuth-nanocrystal/germanium-nanowire junctions. Heat transport calculations, back-focal-plane interferometry, and optical images reveal that the bismuth nanocrystal melts during trapping, facilitating tip-to-tail “nanosoldering” of the germanium nanowires. These bismuth-semiconductor interfaces may be useful for quantum computing or thermoelectric applications. In addition, the ability to trap nanostructures in oxygen- and water-free organic media broadly expands the library of materials available for optical manipulation and single-particle spectroscopy.
The use of optical traps has been limited to materials dispersed in aqueous media, which restricts the materials and range of experiments. Here, the authors demonstrate the alignment and assembly of composite structures made of a bismuth nanocrystal and a germanium nanowire in organic solvents.
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