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-%\title{\bf Characterisation of nanostructured thin films}
-%\author{Sam Moore\\ School of Physics, University of Western Australia}
-%\date{April 2012}
-%\maketitle
-
-\begin{center}
- B.Sc. (Hons) Physics Project \par
- {\bf \Large Thesis} \par
- Samuel Moore \\
- School of Physics, University of Western Australia \\
- April 2012
-\end{center}
-\section*{Characterisation of Nanostructured Thin Films}
-{\bf \emph{Keywords:}} surface plasmons, nanostructures, spectroscopy, metallic-blacks \\
-{\bf \emph{Supervisers:}} W/Prof. James Williams (UWA), Prof. Sergey Samarin (UWA) \\
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-
-%\tableofcontents
-
-\section*{Acknowledgements}
-\begin{itemize}
- \item Sergey Samarin
- \item Jim Williams
- \item Paul Guagliardo
- \item Nikita Kostylev
- \item Workshop (for producing electron gun mount?)
- \item Peter Hammond (?)
-\end{itemize}
-
-\section{Introduction}
-\begin{itemize}
- \item Waffle about motivation for the project
- \begin{itemize}
- \item Metal-Black films may have application for ... something.
- \begin{itemize}
- \item Radiometer vanes, IR detectors
- \item Number of applications where high absorbance into IR is required
- \item These have all been studied before though.
- \end{itemize}
- \item The electron spectra of metal-blacks have not yet been examined.
- \item Remarkable difference between Metal-Black films (bad vacuum) and normal metal films (UHV)
- \begin{itemize}
- \item No (detailed/satisfactory) explanation (that I can find...) for difference
- \end{itemize}
- \item Talk about plasmonic based computing? Moore's law? Applications to thin film solar cells?
-
- \end{itemize}
- \item Specific aims of project
- \begin{enumerate}
- \item Surface density of states / band structure of Black-Au films using TCS (The main aim)
- \item Identification of plasmonic effects in Black-Au films (?) (If they even exist!)
- \begin{itemize}
- \item Identify plasmonic effects in Au and Ag films with Ellipsometry (this is fairly simple to do)
- \end{itemize}
- \item Combination of Ellipsometry and TCS to characterise thin films (not just Black-Au)
- \begin{itemize}
- \item Ie: How can one technique be used to support the other?
- \end{itemize}
- \end{enumerate}
- \item Structure of thesis
-\end{itemize}
-
-\section{Overview of Theory}
-Summarise the literature, refer to past research etc
-
-\subsection{Electron Spectra of a Surface}
-\begin{itemize}
- \item Description of the near surface region
- \begin{itemize}
- \item All real solids occupy finite volumes in space.
- \item The surface of a solid is important because interactions between the solid and its surroundings occur in the near surface region.
- \item Characterised physically by:
- \begin{itemize}
- \item Termination of periodic crystal lattice
- \item Violation of geometric order
- \item Distortion of interatomic distances and hence interaction forces
- \item There is a transition ``near surface'' region between bulk and surface properties, roughly 5 atomic distances.
- \end{itemize}
- \item Potential seen by an electron at a surface can differ greatly from the bulk
- \item $\implies$ the electron spectra of the near surface region differs from the bulk spectra
- \item Simplest case: Step potential at surface
- \begin{itemize}
- \item Metal & Semiconductor
- \end{itemize}
- \item In reality,
-
- \end{itemize}
-
- \item The Electron Spectra
- \begin{itemize}
- \item Electron Spectra describes the energy eigenstates for an electron in a Bulk or Surface potential
- \item Characterised by
- \begin{enumerate}
- \item Energy dispersion $E(\vect{k})$
- \begin{itemize}
- \item Dependence of Energy on electron wave vector
- \item Obtained theoretically by solving Scrhrodinger's Equation
- \item For a free electron gas, $E = \frac{\hbar^2 k^2}{2m}
- \item Periodic potential in bulk solid leads to band gap structure of $E(\vect{k})$
- \item Periodic potential $\implies$ E is periodic. Only needs to be defined in first Brillouin zone.
- \end{itemize}
- \item Density of States $N(E)$
- \begin{itemize}
- \item $N(E) = \frac{\Delta N}{\Delta E} = \frac{1}{4\pi^3}\int_S\left(\der{E}{k}\right)^{-1} dS$
- \item Integral is in momentum space over the isoenergetic surface of energy $E$
- \item For a free electron gas, $N(E) = $
- \end{itemize}
- \end{enumerate}
- \end{itemize}
-
- \item Surface states
- \begin{itemize}
- \begin{enumerate}
- \item Tamm States: Periodic potential in solid, free space outside, jump at surface
- \begin{itemize}
- \item Energy eigenvalues lie in the forbidden band of the bulk spectra
- \item Attenuation of eigenvalues from surface to vacuum, oscillation of state within surface
- \item Max electron density occurs on the crystal surface
- \end{itemize}
- \item Shockley states: Potential of surface and bulk cells equal
- \begin{itemize}
- \item Corresond to free valences (dangling bonds) at the surface
- \end{itemize}
- \end{enumerate}
- \item Tamm and Shockley states arise from two extreme models (large change and small change respectively between bulk and surface). In reality, a combination of Tamm and Shockley states appear.
- \end{itemize}
-