-\subsection{Metallic-Black Thin Films}
-\begin{itemize}
- \item How they are made (bad vacuum, in air or a noble gas)
- \begin{itemize}
- \item If made in air, there are usually tungsten oxides present (from filament). Refer to paper by Pfund.
- \end{itemize}
- \item Structural difference between Black-Au and ``Shiny'' (need a better term) Au
- \begin{itemize}
- \item Can include electron microscopy images?
- \item An actual photograph of a Black-Au film? Not necessary?
- \end{itemize}
- \item Pfund (earliest publisher, preparation and general properties)
- \item Louis Harris (most research in 50s and 60s)
- \begin{itemize}
- \item L. Harris mostly did transmission spectroscopy in the far infra red (well beyond the ellipsometer and Ocean Optics spectrometer ranges)
- \item The really crappy measurements I did with the Ocean Optics spectrometer seem to agree with these measurements
- \begin{itemize}
- \item L. Harris' $\lambda$ has a range of 1nm to $100\mu$m; my measurements are only to $1\mu$m
- \item Agreement in first $1\mu$m anyway
- \item I should probably re-do those measurements with a less crappy setup, if I actually want to use them
- \end{itemize}
- \item Harris related the optical properties to the structure of the film (condensor strands) via the electronic properties
- \end{itemize}
- \item Plasmonic effects - Deep R. Panjwani (honours thesis)
- \begin{itemize}
- \item Not sure if I can use an honours thesis as a reference.
- \item Concluded that surface plasmon resonance in Black-Au film on solar cells lead to increase in solar cell efficiency
- \item Used simulation that modelled Black-Au film as spherical balls to show E field increased by plasmon resonance
- \begin{itemize}
- \item Was this model appropriate? Black-Au is more ``smoke'' or ``strand'' like according to other references. Images also do not show ``blob'' like structure.
- \end{itemize}
- \item Need to read this reference more thoroughly
- \end{itemize}
-\end{itemize}
+
+\subsection{Electron Surface Interaction}
+
+
+% Research of Komolov
+
+\subsection{Electron Surface Interaction}
+
+
+\subsection{Plasmons}
+
+\emph{NOTE: To be completely honest, I don't think I can say much about plasmons. The TCS experiment does not detect plasmonic behaviour. The Ellipsometer can be used to determine frequencies at which plasmons might occur. However, I have not seen any dips in $\epsilon$ which would indicate plasmon thresholds.}
+
+% What are they?
+A plasmon is a quasi-particle arising due to charge density oscillations in a solid.
+
+
+
+% Early research
+
+\subsection{Metallic-Black Films}
+
+% What are they?
+So called metallic-black films are the result of deposition of metal elements at a relatively high pressure (of the order of $10^{-2}$ mbar). The films are named due to their high absorbance at visible wavelengths; they appear black to the naked eye. There is a remarkable contrast between such films and films deposited under low pressure (less than $10^{-6}$mbar), which are typically highly reflective and brightly coloured.
+
+% First mentions and early research; Pfund
+This phenomenom has been known since the early 20th century, with the first papers on the subject published by Pfund in the 1930s \cite{pfund1930}, \cite{pfund1933}. Pfund established the conditions for formation of metallic-blacks \cite{pfund1930}, and showed that the transmission spectrum of metallic black films is almost zero in visible wavelengths, but increases to a plateau in the far infrared \cite{pfund1933}. More extensive research on the structural and optical properties of these films by Louis Harris and others during the 1940s and 1950s \cite{harris1948}, \cite{harris1952}, \cite{harris1953}. It has been established that metallic blacks may be prepared in either air or inert gases
+
+
+% Pretty pictures for purpose of this discussion
+% Not really "results", since I didn't make the images
+Secondary Electron Microscope (SEM) images of Au deposited on Si at high and low pressures (in air) were produced at the Centre for Microscopy Characterisation and Analysis (CMCA), UWA. The film imaged on the left (high pressure) appears black at visible wavelengths, whilst the film on the right (low pressure) appears golden yellow.
+
+\begin{center}
+
+
+\begin{tabular}{cc}
+ \includegraphics[scale=0.2]{figures/Au_BLACK_200nm.png} & %\captionof{figure}{Au-Black SEM Image} \label{Au_BLACK_200nm.png} &
+ \includegraphics[scale=0.2]{figures/Au_semi-shiny_1_SEM.png} %\captionof{figure}{Au SEM Image} \label{Au_semi-shiny_1_SEM.png}
+
+ \label{SEM_images}
+\end{tabular}
+
+ \captionof{figure}{{\bf SEM images of Au deposited on Si at $2\times10^{-2}$mbar (left) and $1\times10^{-6}$mbar.} Note that the scales are very similar for both images.}
+
+\end{center}
+
+% Explanation of structure?
+The structural difference between the two films is striking, and yet the exact mechanism behind the formation of the metallic-black film is not well understood. The most widely accepted explanation is that the evaporated metal particles reaching the target surface have insufficient energy to form a regular crystal lattice due to cooling through collisions with the atmosphere \cite{}. As of yet, there is no detailed theoretical description of this behaviour.
+
+% Research by Harris concluding ``condensor'' like structure
+Harris et al. have produced experimental results of the transmission of metallic-black films from visible wavelengths to the far-infrared \cite{}. By modelling the film as a layer of metallic strands, acting as ``condensors'', Harris et al. arrived at an expression for the electron relaxation time of [element]-black \cite{}, leading to a a transmission spectrum in good agreement with experimental results.
+
+% Mckenzie
+Mckenzie has established that the presence of oxygen effects the optical and electrical properties of metallic-blacks \cite{mckenzie2006}.
+
+% Model of structure
+Nanostructured metal films prepared at low pressure are often approximated by an isotropic layer of spherical blobs upon the substrate, or even as a uniform layer with an ``effective'' thickness \cite{}. As the right image in Figure \ref{SEM_images} shows, this is a good representation of the structure of such a film. In contrast, the metallic-black film is highly non-uniform; as a result, detailed characterisation of the properties of such a film is difficult.
+
+
+
+
+% More recent research
+More recently, it was shown that Au-black coatings increased the efficiency of thin film solar cells \cite{}. In this study, a simulation approximating an Au-black film as a layer of semi-spherical structures showed plasmonic behaviour which lead to an increase in electric field behind the film.
+
+
+% Artificially ``blackened'' thin films
+Metallic-black films have proven useful in applications requiring efficient absorption of light, including the. Recently there has been interest in artificial ``blackening'' of metal surfaces in ways which simplify the characterisation of the surfaces for practical applications.
+
+Sondergaard et al. have produced metallic-black surfaces capable of suporting surface plasmon modes \cite{sondergaard2012}. These films exhibit similar optical properties to the previously considered ``evaporated'' metallic-black surfaces.
+
+% What I will be doing with metallic-black films
+This project will employ Total Current Specroscopy, Ellipsometry and Optical Spectroscopy methods to investigate the difference between metallic films deposited at low pressure, and high pressure (metallic-blacks). The production and study of artificially blackened films is beyond the scope of this research.
+
+
+\begin{center}
+ \includegraphics[scale=0.2]{figures/300V-01.jpg}
+ \captionof{figure}{{\bf Au-black film viewed at magnifications of x20000, x50000, x100000 and x200000} (top left, top right, bottom left, bottom right). The film appears non-isotropic, and possibly fractal like upon magnification. This structure has lead some reasearchers to refer to the deposited films as ``smokes'' \cite{}.}
+ \label{300V-01.jpg}
+\end{center}
+
+\pagebreak