Semiconductor Nanowire Synthesis and Characterization
(Faculty mentor: Joan Redwing)
Nanoelectronic devices assembled from structures
such as nanotubes and nanowires have tremendous potential for a wide range of
applications. They may serve as detectors in chemical and biological sensing
applications or as interconnects in high density molecular electronic circuits.
The unique electronic and optical characteristics that arise in low dimensional
semiconductor nanostructures due to quantum confinement are also of interest
for devices such as quantum transistors and nanoscale light emitters.
We are working on novel methods to synthesize,
assemble and study semiconductor nanowires that may serve as building blocks
for future nanoscale devices and circuits. We have developed a technique to
synthesize silicon nanowires with controlled diameters and lengths by utilizing
nanoporous membranes, shown in Figure 1, as templates for metal catalyzed
crystal growth. The nanowires grow inside the pores of the membrane, which
serve to define the final diameter of the wires. Wet etching is used to release
the wires from the membrane into solution. A sample of silicon nanowires
fabricated using this technique is shown in Figure 2. We are working on methods
to control the conductivity of the wires through intentional doping as well as
the fabrication of junctions and heterostructure in the wires. This project
involves fabrication work as well as optical and electrical characterization to
study the properties of the nanowires.
