Barrier height measurement of metal contacts to Si nanowires using internal photoemission of hot carriers

Kunho Yoon, Jerome K. Hyun, Justin G. Connell, Iddo Amit, Yossi Rosenwaks, Lincoln J. Lauhon*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

24 Scopus citations

Abstract

Barrier heights between metal contacts and silicon nanowires were measured using spectrally resolved scanning photocurrent microscopy (SPCM). Illumination of the metal-semiconductor junction with sub-bandgap photons generates a photocurrent dominated by internal photoemission of hot electrons. Analysis of the dependence of photocurrent yield on photon energy enables quantitative extraction of the barrier height. Enhanced doping near the nanowire surface, mapped quantitatively with atom probe tomography, results in a lowering of the effective barrier height. Occupied interface states produce an additional lowering that depends strongly on diameter. The doping and diameter dependencies are explained quantitatively with finite element modeling. The combined tomography, electrical characterization, and numerical modeling approach represents a significant advance in the quantitative analysis of transport mechanisms at nanoscale interfaces that can be extended to other nanoscale devices and heterostructures.

Original languageEnglish (US)
Pages (from-to)6183-6188
Number of pages6
JournalNano letters
Volume13
Issue number12
DOIs
StatePublished - Dec 11 2013

Keywords

  • Nanowire
  • SPCM
  • Schottky barrier
  • hot electrons
  • internal photoemission
  • metal semiconductor interface

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Barrier height measurement of metal contacts to Si nanowires using internal photoemission of hot carriers'. Together they form a unique fingerprint.

Cite this