Physical observation of a thermo-morphic transition in a silicon nanowire

ACS Nano. 2012 Mar 27;6(3):2378-84. doi: 10.1021/nn2046295. Epub 2012 Feb 24.

Abstract

A thermo-morphic transition of a silicon nanowire (Si-NW) is investigated in vacuum and air ambients, and notable differences are found under each ambient. In the vacuum ambient, permanent electrical breakdown occurs as a result of the Joule self-heating arising from the applied voltage across both ends of the Si-NW. The resulting current abruptly declines from a maximum value at the breakdown voltage (V(BD)) to zero. In addition, the thermal conductivity of the Si-NW is extracted from the V(BD) values under the vacuum ambient and shows good agreement with previously reported results. While the breakdown of the Si-NW does not exhibit negative differential resistance under the vacuum ambient, it interestingly shows negative differential resistance with multiple resistances in the current-voltage characteristics under the air ambient, similar to the behavior of carbon nanotubes. This behavior is triggered by current-induced oxidation, which leads to the thermo-morphic transition observed by TEM analyses. Additionally, the current-induced oxidation is favorably applied to reduce the size of a Si-NW at a localized and designated point.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electric Conductivity
  • Nanowires / chemistry*
  • Oxidation-Reduction
  • Silicon / chemistry*
  • Temperature*

Substances

  • Silicon