Metal-insulator transition in films of doped semiconductor nanocrystals

Ting Chen, K. V. Reich, Nicolaas J. Kramer, Han Fu, Uwe R. Kortshagen, B. I. Shklovskii

Research output: Contribution to journalArticlepeer-review

107 Scopus citations

Abstract

To fully deploy the potential of semiconductor nanocrystal films as low-cost electronic materials, a better understanding of the amount of dopants required to make their conductivity metallic is needed. In bulk semiconductors, the critical concentration of electrons at the metal-insulator transition is described by the Mott criterion. Here, we theoretically derive the critical concentration nc for films of heavily doped nanocrystals devoid of ligands at their surface and in direct contact with each other. In the accompanying experiments, we investigate the conduction mechanism in films of phosphorus-doped, ligand-free silicon nanocrystals. At the largest electron concentration achieved in our samples, which is half the predicted nc, we find that the localization length of hopping electrons is close to three times the nanocrystals diameter, indicating that the film approaches the metal-insulator transition.

Original languageEnglish (US)
Pages (from-to)299-303
Number of pages5
JournalNature Materials
Volume15
Issue number3
DOIs
StatePublished - Mar 1 2016

Bibliographical note

Publisher Copyright:
© 2016 Macmillan Publishers Limited. All rights reserved.

MRSEC Support

  • Primary

PubMed: MeSH publication types

  • Journal Article
  • Research Support, Non-U.S. Gov't

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