Noncontact friction of a semiconductor with charge carriers of differing mobilities
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Updated: Oct 25, 2026

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1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.
Abstract:
The coefficient of noncontact friction as measured in an electric force microscopy experiment is computed for a semiconductor with positive and negative charge carriers of distinct mobilities. The friction is determined for a sample represented by classical electrodynamics coupled to diffusing carriers in a dielectric continuum. The analysis generalizes previous work in which positive and negative carriers were taken to have identical mobilities, allowing application to a wider range of semiconductors. Dielectric and electrical properties of the material are shown to be revealed by the dependence of the friction on experimentally accessible parameters such as probe-sample separation and carrier density.
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