Significant enhancement of hole mobility in [110] silicon nanowires compared to electrons and bulk silicon

Nano Lett. 2008 Feb;8(2):760-5. doi: 10.1021/nl0727314. Epub 2008 Jan 19.

Abstract

Utilizing sp3d5s* tight-binding band structure and wave functions for electrons and holes we show that acoustic phonon limited hole mobility in [110] grown silicon nanowires (SiNWs) is greater than electron mobility. The room temperature acoustically limited hole mobility for the SiNWs considered can be as high as 2500 cm2/V s, which is nearly three times larger than the bulk acoustically limited silicon hole mobility. It is also shown that the electron and hole mobility for [110] grown SiNWs exceed those of similar diameter [100] SiNWs, with nearly 2 orders of magnitude difference for hole mobility. Since small diameter SiNWs have been seen to grow primarily along the [110] direction, results strongly suggest that these SiNWs may be useful in future electronics. Our results are also relevant to recent experiments measuring SiNW mobility.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Computer Simulation
  • Electric Conductivity
  • Electron Transport
  • Electrons
  • Models, Chemical*
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure
  • Nanotechnology / methods*
  • Particle Size
  • Silicon / chemistry*

Substances

  • Silicon