Multiscale Self-Assembly of Silicon Quantum Dots into an Anisotropic Three-Dimensional Random Network


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İlday S. K. , İlday F. Ö. , Huebner R., Prosa T. J. , Martin I., Nogay G., ...More

NANO LETTERS, vol.16, pp.1942-1948, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 16
  • Publication Date: 2016
  • Doi Number: 10.1021/acs.nanolett.5b05158
  • Journal Name: NANO LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1942-1948
  • Keywords: Si, random network, hierarchical, multiscale, self-assembly, stochastic deposition, NANOSTRUCTURES, GROWTH, PHOTOVOLTAICS, NANOPARTICLES, NANOCRYSTALS, PHOTONICS, NANOSCALE, NANOWIRES
  • Middle East Technical University Affiliated: Yes

Abstract

Multiscale self-assembly is ubiquitous in nature but its deliberate use to synthesize multifunctional three-dimensional materials remains rare, partly due to the notoriously difficult problem of controlling topology from atomic to macroscopic scales to obtain intended material properties. Here, we propose a simple, modular, noncolloidal methodology that is based on exploiting universality in stochastic growth dynamics and driving the growth process under far-from-equilibrium conditions toward a preplanned structure. As proof of principle, we demonstrate a confined-but connected solid structure, comprising an anisotropic random network of silicon quantum-dots that hierarchically self-assembles from the atomic to the microscopic scales. First, quantum-dots form to subsequently interconnect without inflating their diameters to form a random network, and this network then grows in a preferential direction to form undulated and branching nanowire-like structures. This specific topology simultaneously achieves two scale-dependent features, which were previously thought to be mutually exclusive: good electrical conduction on the microscale and a bandgap tunable over a range of energies on the nanoscale.