Spray-coating route for highly aligned and large-scale arrays of nanowires

ACS Nano. 2012 Jun 26;6(6):4702-12. doi: 10.1021/nn204513y. Epub 2012 May 11.

Abstract

Technological implementation of nanowires (NWs) requires these components to be organized with controlled orientation and density on various substrates. Here, we report on a simple and efficient route for the deposition of highly ordered and highly aligned NW arrays on a wide range of receiver substrates, including silicon, glass, metals, and flexible plastics with controlled density. The deposition approach is based on spray-coating of a NW suspension under controlled conditions of the nozzle flow rate, droplet size of the sprayed NWs suspension, spray angle, and the temperature of the receiver substrate. The dynamics of droplet generation is understood by a combined action of shear forces and capillary forces. Provided that the size of the generated droplet is comparable to the length of the single NW, the shear-driven elongation of the droplets results presumably in the alignment of the confined NW in the spraying direction. Flattening the droplets upon their impact with the substrate yields fast immobilization of the spray-aligned NWs on the surface due to van der Waals attraction. The availability of the spray-coating technique in the current microelectronics technology would ensure immediate implementation in production lines, with minimal changes in the fabrication design and/or auxiliary tools used for this purpose.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallization / methods
  • Gases / chemistry*
  • Macromolecular Substances / chemistry
  • Materials Testing
  • Microfluidics / methods*
  • Molecular Conformation
  • Nanoparticles / chemistry*
  • Nanoparticles / ultrastructure*
  • Particle Size
  • Surface Properties

Substances

  • Gases
  • Macromolecular Substances