Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 61: Quantum Dots and Wires: Transport Properties
HL 61.6: Vortrag
Mittwoch, 9. März 2016, 16:30–16:45, H16
Electronic Structure and Transport Properties of Thin Silicon Nanowires — •Florian Fuchs1,2,3, Sibylle Gemming1,3, and Jörg Schuster4 — 1Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany — 2Center for Advancing Electronics Dresden (cfaed), Dresden, Germany — 3Institute of Physics, Technische Universität Chemnitz, Chemnitz, Germany — 4Fraunhofer Institute for Electronic Nano Systems, Chemnitz, Germany
Silicon nanowires (SiNWs) are promising candidates as building blocks for electronic devices. For the simulation of SiNWs, numerical device simulations, based on the silicon bulk band structure, are often used. When the diameter of the wires is reduced, however, atomistic quantum simulations become mandatory at some point.
In the present work, thin hydrogen-passivated SiNWs with diameters between 1 and 6 nm are studied by means of density functional theory. It is shown that the band gap approaches the bulk value in the limit of infinitely thick nanowires and increases for thin wires due to quantum confinement. Using a radially resolved density of states it is demonstrated, that the density of states is highest in the nanowire center, where most of the current transport would occur, and decreases near the surface. Comparing the density of states between SiNWs with different diameters, the transition to bulk silicon can be observed. This justifies the use of bulk band structure approximations for thicker SiNWs, but also highlights the need for atomistic quantum simulations in case of thinner ones.