Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 6: Quantum dots and wires: Transport properties I
HL 6.3: Vortrag
Montag, 27. März 2006, 10:45–11:00, BEY 118
Resonant Tunneling in GaAs/AlAs Nanocolumns Improved by Quantum Collimation — •Jakob Wensorra1, Klaus Michael Indlekofer1, Mihail Ion Lepsa1, Arno Förster2, and Hans Lüth1 — 1Institut für Schichten and Grenzflächen (ISG1) und Center of Nanoelectronic Systems for Information Technology (CNI), Forschungszentrum Jülich GmbH, 52425 Jülich — 2Fachhochschule Aachen, Abteilung Jülich, Physikalische Technik, Ginsterweg 1, 52428 Jülich
DC electrical measurements on top-down processed resonant tunneling GaAs/AlAs nanocolumns have been carried out at room temperature. The dependence of the I-V characteristics on the device dimension has shown that the electronic transport properties of the smallest devices are strongly influenced by the lateral depletion region, which defines the vertical conductive channel within the device. In the I-V characteristics, a clearly pronounced region of negative differential conductance has been observed, down to 50 nm lateral dimensions. Simulations of the 2D-potential map of the device structure by means of a self-consistent semi-classical drift-diffusion solver suggest a transport model based on a quantum collimation effect [1] due to a sadle point in the potential profile. For the ultimately scaled structures, this quantum collimation effect can lead to a distinct improvement of the nanodevice performance at room temperature.
[1] J. Wensorra, K. M. Indlekofer, M. I. Lepsa, A. Förster, and H. Lüth, Nano Letters 10.121/nl051781a (2005).