Bismuth nanowire and antidot array studies motivated by thermoelectricity

Porous anodic alumina (PAA) films were utilized to template the fabrication of nanostructures of bismuth, antimony and bismuth-antimony alloys. The cylindrical template pores were used to synthesize nanowires by electrochemical methods. The porous surface of the template was used as a substrate for the e-beam deposition of antidot array thin films. Electrical transport measurements in bismuth nanowire arrays embedded in the templates were demonstrated to be highly sensitive to structural imperfections. Thin film studies compared the weak anti-localization effect in bismuth films with antidot array morphology versus continuous films. It is shown that the antidot array makes the weak anti-localization effect more pronounced in magnetoresistance measurements, and allows for a more detailed study of carrier scattering mechanisms in thin films. A new process is presented for the fabrication of PAA templates on rigid substrates. The substrate provides mechanical support for the generation of crack-free PAA films over areas of tens of cm2, while electrically-conducting substrates can serve as back-electrodes for the electrochemical growth of nanowires and for their electrical characterization. Various processing challenges were solved, including the deposition of thick aluminum films, the control over the adhesion between the layers of the structure, and the removal of the alumina barrier-layer at the interface between the porous film and the substrate. The use of the substrate to achieve non-planar and patterned PAA films is demonstrated.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Rabin, Oded, 1974-

Advisor dc:contributor.advisor

• Mildred S. Dresselhaus.

• Chemistry.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/17738

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/17738