Charge transport in nanoscale "all-inorganic" networks of semiconductor nanorods linked by metal domains

Romain Lavieville, Yang Zhang, Alberto Casu, Alessandro Genovese, Liberato Manna, Enzo Di Fabrizio, Roman Krahne*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

37 Scopus citations

Abstract

Charge transport across metal-semiconductor interfaces at the nanoscale is a crucial issue in nanoelectronics. Chains of semiconductor nanorods linked by Au particles represent an ideal model system in this respect, because the metal-semiconductor interface is an intrinsic feature of the nanosystem and does not manifest solely as the contact to the macroscopic external electrodes. Here we investigate charge transport mechanisms in all-inorganic hybrid metal-semiconductor networks fabricated via self-assembly in solution, in which CdSe nanorods were linked to each other by Au nanoparticles. Thermal annealing of our devices changed the morphology of the networks and resulted in the removal of small Au domains that were present on the lateral nanorod facets, and in ripening of the Au nanoparticles in the nanorod junctions with more homogeneous metal-semiconductor interfaces. In such thermally annealed devices the voltage dependence of the current at room temperature can be well described by a Schottky barrier lowering at a metal semiconductor contact under reverse bias, if the spherical shape of the gold nanoparticles is considered. In this case the natural logarithm of the current does not follow the square-root dependence of the voltage as in the bulk, but that of V 2/3. From our fitting with this model we extract the effective permittivity that agrees well with theoretical predictions for the permittivity near the surface of CdSe nanorods. Furthermore, the annealing improved the network conductance at cryogenic temperatures, which could be related to the reduction of the number of trap states.

Original languageEnglish (US)
Pages (from-to)2940-2947
Number of pages8
JournalACS Nano
Volume6
Issue number4
DOIs
StatePublished - Apr 24 2012

Keywords

  • Schottky-Richardson model
  • charge transport
  • metal-semiconductor nanojunction
  • networks
  • self-assembly
  • thermionic emission

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

Fingerprint

Dive into the research topics of 'Charge transport in nanoscale "all-inorganic" networks of semiconductor nanorods linked by metal domains'. Together they form a unique fingerprint.

Cite this