TY - THES

T1 - Topography and conductivity measurements on nanostructures using atomic-force microscopy

AU - Hou, Yue

N1 - embargoed until null

PY - 2007

Y1 - 2007

N2 - Due to its imaging principle, Atomic-Force Microscopy (AFM) allows quantitative morphological characterization of surface nanostructrues. Furthermore, using a conductive probe, AFM enables investigation of electrical properties on the nanometer scale. Here, the first capability of AFM is applied to investigate a new class of materials, semiconductor nanorods, whereas conductive atomic-force microscopy (C-AFM) is employed to perform conductivity measurements in piezoelectric ceramics. Semiconductor nanorods have gained much attention due to their potential applications in the fields of photonic and sensing devices, where it is necessary to control the rod position, direction, and shape. Topographical information on 3D shape, average diameter and height fluctuations of upright standing ZnO nanorods, were obtained, and an intermediate facet between (0001) top facets and perpendicular {10-10} side facets has been found. For the Si nanorods grown on Si (111), the facet sequences of the rod sides can be determined, confirming transmission electron microscopy results. Piezoelectric actuators are widely used devices. To improve their performance, detailed investigation of the interface between metal electrode and ceramic matrix is required. C-AFM was used for investigating the local electrical conductivity of cross sectional PZT samples. The obtained results demonstrate the analytical capabilities of C-AFM technique for spatially resolved electrical investigations of PZT.

AB - Due to its imaging principle, Atomic-Force Microscopy (AFM) allows quantitative morphological characterization of surface nanostructrues. Furthermore, using a conductive probe, AFM enables investigation of electrical properties on the nanometer scale. Here, the first capability of AFM is applied to investigate a new class of materials, semiconductor nanorods, whereas conductive atomic-force microscopy (C-AFM) is employed to perform conductivity measurements in piezoelectric ceramics. Semiconductor nanorods have gained much attention due to their potential applications in the fields of photonic and sensing devices, where it is necessary to control the rod position, direction, and shape. Topographical information on 3D shape, average diameter and height fluctuations of upright standing ZnO nanorods, were obtained, and an intermediate facet between (0001) top facets and perpendicular {10-10} side facets has been found. For the Si nanorods grown on Si (111), the facet sequences of the rod sides can be determined, confirming transmission electron microscopy results. Piezoelectric actuators are widely used devices. To improve their performance, detailed investigation of the interface between metal electrode and ceramic matrix is required. C-AFM was used for investigating the local electrical conductivity of cross sectional PZT samples. The obtained results demonstrate the analytical capabilities of C-AFM technique for spatially resolved electrical investigations of PZT.

KW - Rasterkraftmikroskopie (AFM) Leitfähigkeits-Rasterkraftmikroskopie (C-AFM) ZnO-Nanostäbe Si-Nanostäbe Facetten piezoelektrische Keramik

KW - Atomic-Force Microscopy (AFM) conductive atomic-force microscopy (C-AFM) ZnO nanorods Si-nanorods piezoelectric ceramic

M3 - Diploma Thesis

ER -