Variation in the hopping exponent in disordered silicon MOSFETs

Ferrus, T., George, R., Barnes, C. H. W., Lumpkin, N., Paul, D. J. and Pepper, M. (2008) Variation in the hopping exponent in disordered silicon MOSFETs. Journal of Physics: Condensed Matter, 20(41), p. 415226. (doi: 10.1088/0953-8984/20/41/415226)

Abstract

We observe a complex change in the hopping exponent value from 1/2 to 1/3 as a function of disorder strength and electron density in a sodium-doped silicon MOSFET (metal-oxide-semiconductor field effect transistor). The disorder was varied by applying a gate voltage and thermally drifting the ions to different positions in the oxide. The same gate was then used at low temperature to modify the carrier concentration. Magnetoconductivity measurements are compatible with a change in transport mechanisms when either the disorder or the electron density is modified, suggesting a possible transition from a Mott insulator to an Anderson insulator in these systems.

• Item Type: Articles
• Keywords: silicon
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Paul, Professor Douglas
• Authors: Ferrus, T., George, R., Barnes, C. H. W., Lumpkin, N., Paul, D. J., and Pepper, M.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Journal of Physics: Condensed Matter
• ISSN: 0953-8984