Reversible Metal-Insulator Transition in Ordered Metal Nanocrystal Monolayers Observed by Impedance Spectroscopy

Gil Markovich; Charles P. Collier; James R. Heath

doi:10.1103/PhysRevLett.80.3807

Reversible Metal-Insulator Transition in Ordered Metal Nanocrystal Monolayers Observed by Impedance Spectroscopy

Gil Markovich, Charles P. Collier, and James R. Heath

Phys. Rev. Lett. 80, 3807 – Published 27 April 1998

Abstract

Low frequency impedance spectroscopy was applied on a Langmuir monolayer of alkylthiol passivated 35 Å diameter silver quantum dots, as a function of interparticle separation distance. As interparticle spacing decreases below 30% of particle diameter, a reduction in interparticle charge tunneling time is observed. On further compression, the complex impedance of the films undergoes a transition from a parallel $RC$ equivalent circuit to an inductive circuit. Optical reflectance changes in the films are consistent with the deduced metal-insulator transition.

Received 3 November 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.3807

Authors & Affiliations

Gil Markovich¹, Charles P. Collier², and James R. Heath^1,*

¹Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095-1569
²Department of Chemistry, University of California, Berkeley, California 94720-1460