Impurity-Scattering Limited Electron Mobility in Free Standing Quantum Wires: Image Charge Effect
P. Vagner and M. Mos̆ko
Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 842 39 Bratislava, Slovakia
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We calculate the impurity-scattering limited mobility of the one-dimensional electron gas in a rectangular GaAs quantum wire confined in the vertical (growth) direction by n-modulation doped AlGaAs layers and free standing along the transverse direction. The scattering potential of the ionized impurity is obtained by solving the Poisson equation with z-dependent electrostatic permittivity in order to take into account the image charge effect due to the abrupt permittivity change at the GaAs/air interfaces. We show that the "image impurity" scattering tends to drastically reduce the electron mobility for sufficiently small (≈10 nm) transverse wire widths.
DOI: 10.12693/APhysPolA.90.1103
PACS numbers: 73.50.-h, 73.50.Bk