Novel Nanostructure Fabrication and Characterization
One dimensional (1D) nanowires or nanorods are anisotropic nanostructures with large aspect ratio (length/diameter), with diameters of 1 – 200 nanometers and length up to several tens micrometers. They are nanoscale building blocks that may provide break-through applications in nanoelectronics, photonics, and bioengineering, and which have stimulated great research interest. They are ideal systems for investigating the dependence of the physical properties, such as electric, magnetic, optic and mechanical characteristics, on size and dimensionality. They are also expected to play an essential role as both interconnects and functional components in the fabrication of nanoscale electronic and optoelectronic devices. Many unique and fascinating properties have already been demonstrated, such as superior mechanical toughness, higher luminescence efficiency, enhancement of thermoelectric figure of merit and lowered lasing threshold. Homogeneous nanowires and nanowire networks have been previously used as chemical sensors, field-effect transistors and inverters, photodetectors, light-emitting diodes and laser, and logic gates. Very recently, by alternating the compositions of the nanostructures during fabrication, a so-called “superlattice” nanowire has been demonstrated which can greatly increase the versatility and application of these building blocks in nanoscale electronic, photonic, and biological applications. Possible applications, including thermoelectrics, nanobarcodes, injection lasers, and one-dimensional waveguides, could be implemented through these superlattice nanostructure building blocks.
We are interested in fabricating various novel one-dimensional nanostructures using different preparation techniques. One unique technique is so-called glancing angle deposition, and we can control the morphology of the nanostructure by computer program (http://www.physast.uga.edu/~zhaoy/glad.html). Other techniques include chemical vapor deposition method and pulsed laser deposition method. In addition, we will also incorporate electron beam lithography technique to grow patterned nanostructures. In this project, student will have a chance to learn fundamentals on vacuum science, surface science, and nanotechnology, and have a chance to access state-of-art nanofabrication facilities such as e-beam evaporation/sputtering system, chemical vapor deposition system, pulsed laser deposition system, e-beam lithography tool, as well as characterization facilities such as scanning electron microscope, transmission electron microscope, and atomic force microscope. We hope the student can build very good hands-on experience.