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MM: Fachverband Metall- und Materialphysik

MM 32: Topical Session Multifunctional Materials I

MM 32.4: Vortrag

Mittwoch, 24. März 2010, 11:30–11:45, H6

Nanowire-based sensors for chemical species — •Dawit Gedamu, Maria Kassab, Seid Jebril, and Rainer Adelung — Kaiserstr. 2, 24143 Kiel

ZnO has been given lots of attention as it is promising multifunctional material for various applications because of its large direct band gap of 3.37 eV at room temperature and large exciton binding energy of 60 meV. Change in electrical conductance of ZnO thick film , nanostructures , nanowires is reported when such structures are exposed to different chemical species. In this work, a nanowire of ZnO was chosen since such structure has an immense surface area to volume ratio. A suitable and cost effective approach called thin film fracture approach is used to fabricate the nanowire . Under ambient conditions both thin film and nanowire of ZnO deposited by RF sputtering were found to show electrically insulating behavior. Post annealing above 600 K in ambient condition for about 1 hour however has resulted in electrical conductance in both the thin film and the nanowire. When such a nanowire is exposed to oxygen, it shows a quick variation in the electrical conductance for different oxygen concentrations (pressures). Gold (Au) nanowires produced with such a approach were also studied for bio-sensor application. [1] E. S. Jung et al, phys. stat. sol. (b) 244, 5, 1553 (2007) [2] S. Kim and J. Maier Electr. Sol. Stat. Lett. 6 (11), J7 (2003) [3] Chien-Yuan Lu et al, IEEE SENS. J. 9, 4 (2009) [4] S. Jebril et al. Small 4, 2214 (2008).