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HL: Fachverband Halbleiterphysik
HL 93: Poster Session: Metal-Semiconductor Hybrid Systems, Plasmonic Systems / Photonic Crystals / Carbon: Diamond & CNT / Quantum Information Systems
HL 93.18: Poster
Donnerstag, 29. März 2012, 16:00–19:00, Poster D
Ab initio simulations of CNTs for sensor application — •Christian Wagner1, Jörg Schuster1,2, and Thomas Gessner1,2 — 1Center for Microtechnologies, Chemnitz University of Technology, 09107 Chemnitz — 2Fraunhofer Institute for electrical nanosystems ENAS, Technologie-Campus 3, 09126 Chemnitz
Carbon nanotubes (CNTs) are of great interest e.g. for sensor application because of their unique properties. Small-gap single-wall CNTs (sgSWCNTs) show a change of resistivity over several orders of magnitude while being strained only by a few percent. This is due to strain-induced band gap opening of sgSWCNTs. They are mechanically stable as well and show high fracture strain. Thus, they are favorable candidates for the application in nano-scaled, mechanical sensors.
Within the group of sgSWCNTs only a few are of practical relevance due to chemical selection methods. Thus we present DFT-calculations of the piezoresistive effect of such application-relevant CNTs. We investigated the band gap by means of DFT and compare our results with analytical tight-binding models, accessible in literature [1, 2], and published DFT-results.
Until now, only ideal CNTs have been considered for ab-initio, piezoresistance calculations. As real CNTs contain defects, we present first results of defective CNTs.
[1] Yang, L. and Han, J., Electronic Structure of Deformed Carbon Nanotubes, Phys. Rev. Lett. 85, 154-157, 2000
[2] Kleiner, A. and Eggert, S., Band gaps of primary metallic carbon nanotubes, Phys. Rev. B 63, 073408, 2001