Document Type
Thesis - University Access Only
Award Date
2012
Degree Name
Master of Science (MS)
Department / School
Electrical Engineering and Computer Science
First Advisor
Mahdi Farrokh Baroughi
Abstract
Nanostructure arrays have shown strong potential for enhancing optical path length and light scattering in photovoltaics (PVs) and near field electromagnetic field enhancement for plasmonic applications. One of the widely used methods for nanopillars fabrication is vapor-liquid-solid method. However, the remnants of the metal catalyst act as deep level traps and seriously reduce the efficiency of the solar cell. Although optical and electron beam lithography have been utilized for development of Si nanopillar arrays these methods are expensive when fabricating deep sub-micron regime nanostructures. Self-assembly of silica nano beads followed by reactive ion etching of Si substrate using the self-assembled particles as the etching mask, has gained significant attention for development of Si nanopillars. This method has advantages over vapor-liquid-solid and electron beam or optical lithography due to low cost and no chance of metal contamination. Successful utilization of this method in PVs and plasmonics require stringent control of geometrical parameters such as nanopillar diameter, spacing and shape. A novel sequence of fabrication steps have been developed to synthesize Si and gold nanopillars with controlled diameter, height, and spacing. The diameter and spacing of the nanopillars can be controlled by the diameter of the nano beads through the duration of the isotropic SiO2 etch. The height of the nanopillars can be controlled by varying the duration of anisotropic Si etch. Gold nanopillar arrays have also been developed for plasmonic application by conformal deposition of gold on Si nanopillars. These nanostructures can be used in solar cell and plasmonic applications to enhance the efficiencies of solar cells.
Library of Congress Subject Headings
Nanostructures
Solar cells
Silicon solar cells
Photovoltaic power generation
Plasmons (Physics)
Publisher
South Dakota State University
Recommended Citation
Gautam, Umesh, "Controlled Synthesis of Silicon Nanopillar Array for Photovoltaic and Plasmonic Applications" (2012). Electronic Theses and Dissertations. 1911.
https://openprairie.sdstate.edu/etd2/1911
Rights Statement
