Nupur Gupta, Yipu Song, Gregory W. Holloway, Urbasi Sinha, Chris Haapamaki, Ray R. LaPierre, Jonathan Baugh
Effective electron mobilities are obtained by transport measurements on InAs nanowire field-effect transistors at temperatures ranging from 10-200 K. The mobility-versus-temperature is found to have a positive slope at temperatures below ~ 30-50 K, which turns over to a negative slope at higher temperatures. The magnitude and temperature dependence of the observed mobility are both explained by the identification of Coulomb scattering from ionized surface states as the dominant scattering mechanism. The negative slope above 50 K is primarily due to the thermally activated increase in the number of scatterers, although nanoscale confinement also plays a role as higher radial subbands are populated, leading to interband scattering and a shift of the carrier distribution closer to the surface. Scattering rate calculations using finite-element simulations of the nanowire transistor confirm that these mechanisms can fully explain the experimental data.
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http://arxiv.org/abs/1210.3665
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