diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..bf7604d --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +*~ +*# diff --git a/WellBandStructure.png b/WellBandStructure.png new file mode 100644 index 0000000..32cee82 Binary files /dev/null and b/WellBandStructure.png differ diff --git a/coursework.lyx b/coursework.lyx index a66d58f..c46710a 100644 --- a/coursework.lyx +++ b/coursework.lyx @@ -43,9 +43,11 @@ \use_package stackrel 1 \use_package stmaryrd 1 \use_package undertilde 1 -\cite_engine basic -\cite_engine_type default +\cite_engine biblatex +\cite_engine_type authoryear \biblio_style plain +\biblatex_bibstyle ieee +\biblatex_citestyle ieee \use_bibtopic false \use_indices false \paperorientation portrait @@ -97,6 +99,393 @@ Quantum Engineering Design Structure Design \end_layout +\begin_layout Standard +In order to design a quantum well which emits light of wavelength 1.55μm, + a well material must be chosen such that an interband electron transition + emits photons of this wavelength. +\end_layout + +\begin_layout Standard +This band gap energy can be found from the equation +\end_layout + +\begin_layout Standard +\begin_inset Formula +\[ +E=hf +\] + +\end_inset + + +\end_layout + +\begin_layout Standard +When considering photons, +\begin_inset Formula $f$ +\end_inset + + can be substituted with +\end_layout + +\begin_layout Standard +\begin_inset Formula +\[ +f=\frac{c}{\lambda} +\] + +\end_inset + + +\end_layout + +\begin_layout Standard +In order to find the +\begin_inset Formula $E$ +\end_inset + + in terms of wavelength +\end_layout + +\begin_layout Standard +\begin_inset Formula +\[ +E=\frac{hc}{\lambda} +\] + +\end_inset + + +\end_layout + +\begin_layout Standard +Returning to the specifications, this allows 1.55μm to be expressed as 1.28x10 +\begin_inset script superscript + +\begin_layout Plain Layout +-19 +\end_layout + +\end_inset + + J or approximately 0.8 eV. +\end_layout + +\begin_layout Standard +This energy value will be the same as the total band gap for the well from + the first hole energy level to the first electron enery level, shown as +\end_layout + +\begin_layout Standard +\begin_inset Formula +\[ +\varSigma E_{g}=E_{1h}+E_{g}+E_{1e}\thickapprox0.8eV +\] + +\end_inset + + +\end_layout + +\begin_layout Standard +see figure +\begin_inset CommandInset ref +LatexCommand ref +reference "fig:Well-Band-structure" +plural "false" +caps "false" +noprefix "false" + +\end_inset + +. +\end_layout + +\begin_layout Standard +\begin_inset Float figure +wide false +sideways false +status open + +\begin_layout Plain Layout +\align center +\begin_inset Graphics + filename WellBandStructure.png + lyxscale 40 + width 60col% + +\end_inset + + +\begin_inset Caption Standard + +\begin_layout Plain Layout +Band structure of an AlGaAs/GaAs/AlGaAs quantum well including discrete + energy levels +\begin_inset CommandInset citation +LatexCommand cite +key "ieee_s6824198" +literal "false" + +\end_inset + + +\begin_inset CommandInset label +LatexCommand label +name "fig:Well-Band-structure" + +\end_inset + + +\end_layout + +\end_inset + + +\end_layout + +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $E_{g}$ +\end_inset + + should be the dominant term in this equation and as such in investigating + suitable materials, the bulk band gap should be close to but lower than + 0.8eV. +\end_layout + +\begin_layout Standard +None of the binary III-V Indium based alloys have bulk band gaps in a suitable + range, as such ternary alloys were investigated. +\end_layout + +\begin_layout Standard +Indium Gallium Arsenide (In +\begin_inset script subscript + +\begin_layout Plain Layout +\begin_inset Formula $x$ +\end_inset + + +\end_layout + +\end_inset + +Ga +\begin_inset script subscript + +\begin_layout Plain Layout +\begin_inset Formula $(1-x)$ +\end_inset + + +\end_layout + +\end_inset + +As) as a well material with Indium Phosphide (InP) as a barrier material + would provide a suitable combination assuming that a composition ratio + +\begin_inset Formula $x$ +\end_inset + + could be found that satisfied the two conditions of having the required + bulk band gap and being lattice matched. + A common ratio in industry is In +\begin_inset script subscript + +\begin_layout Plain Layout +0.53 +\end_layout + +\end_inset + +Ga +\begin_inset script subscript + +\begin_layout Plain Layout +0.47 +\end_layout + +\end_inset + +As and as such this was tested first. +\end_layout + +\begin_layout Subsubsection +Lattice Match +\end_layout + +\begin_layout Standard +Lattice matching is the process of ensuring that two crystalline structures + are of similar dimensions in order to decrease strain at the interface + between the two materials. + This is particularly important for quantum wells formed through epitaxial + growth as strain introduced between such thin layers can cause defects + ultimately negatively affecting it's electronic properties. +\end_layout + +\begin_layout Standard +The lattice constants between the barrier and well materials should be as + close as is deemed acceptable for the application. + The lattice constants for the prospective materials are shown in table + +\begin_inset CommandInset ref +LatexCommand ref +reference "tab:Lattice-constants" +plural "false" +caps "false" +noprefix "false" + +\end_inset + +. +\end_layout + +\begin_layout Standard +\begin_inset Float table +wide false +sideways false +status open + +\begin_layout Plain Layout +\align center +\begin_inset Tabular + + + + + + +\begin_inset Text + +\begin_layout Plain Layout +Material +\end_layout + +\end_inset + + +\begin_inset Text + +\begin_layout Plain Layout +Lattice Constant (Å) +\end_layout + +\end_inset + + + + +\begin_inset Text + +\begin_layout Plain Layout +InAs +\end_layout + +\end_inset + + +\begin_inset Text + +\begin_layout Plain Layout +6.0583 +\end_layout + +\end_inset + + + + +\begin_inset Text + +\begin_layout Plain Layout +GaAs +\end_layout + +\end_inset + + +\begin_inset Text + +\begin_layout Plain Layout +5.653 +\end_layout + +\end_inset + + + + +\begin_inset Text + +\begin_layout Plain Layout +InP +\end_layout + +\end_inset + + +\begin_inset Text + +\begin_layout Plain Layout +5.869 +\end_layout + +\end_inset + + + + +\end_inset + + +\end_layout + +\begin_layout Plain Layout +\begin_inset Caption Standard + +\begin_layout Plain Layout +Lattice constants for prospective well and barrier materials +\begin_inset CommandInset label +LatexCommand label +name "tab:Lattice-constants" + +\end_inset + + +\end_layout + +\end_inset + + +\end_layout + +\begin_layout Plain Layout + +\end_layout + +\end_inset + + +\end_layout + +\begin_layout Standard +In order to compute a compound lattice constant for InGaAs, Vegard's law + can be applied. + Vegard's law provides an approximation for the lattice constant of a solid + solution by +\end_layout + +\begin_layout Subsubsection +Band Gap +\end_layout + \begin_layout Subsection Probability Plot \end_layout @@ -121,6 +510,18 @@ Application of Nanomaterials \end_inset +\end_layout + +\begin_layout Standard +\begin_inset CommandInset bibtex +LatexCommand bibtex +btprint "btPrintCited" +bibfiles "references" +options "bibtotoc" + +\end_inset + + \end_layout \end_body diff --git a/coursework.lyx~ b/coursework.lyx~ deleted file mode 100644 index 78b561f..0000000 --- a/coursework.lyx~ +++ /dev/null @@ -1,128 +0,0 @@ -#LyX 2.3 created this file. For more info see http://www.lyx.org/ -\lyxformat 544 -\begin_document -\begin_header -\save_transient_properties true -\origin unavailable -\textclass article -\use_default_options true -\maintain_unincluded_children false -\language english -\language_package default -\inputencoding auto -\fontencoding global -\font_roman "default" "default" -\font_sans "default" "default" -\font_typewriter "default" "default" -\font_math "auto" "auto" -\font_default_family default -\use_non_tex_fonts false -\font_sc false -\font_osf false -\font_sf_scale 100 100 -\font_tt_scale 100 100 -\use_microtype false -\use_dash_ligatures true -\graphics default -\default_output_format default -\output_sync 0 -\bibtex_command default -\index_command default -\paperfontsize default -\spacing single -\use_hyperref false -\papersize default -\use_geometry true -\use_package amsmath 1 -\use_package amssymb 1 -\use_package cancel 1 -\use_package esint 1 -\use_package mathdots 1 -\use_package mathtools 1 -\use_package mhchem 1 -\use_package stackrel 1 -\use_package stmaryrd 1 -\use_package undertilde 1 -\cite_engine basic -\cite_engine_type default -\biblio_style plain -\use_bibtopic false -\use_indices false -\paperorientation portrait -\suppress_date true -\justification true -\use_refstyle 1 -\use_minted 0 -\index Index -\shortcut idx -\color #008000 -\end_index -\leftmargin 2cm -\topmargin 2cm -\rightmargin 2cm -\bottommargin 2cm -\secnumdepth 3 -\tocdepth 3 -\paragraph_separation indent -\paragraph_indentation default -\is_math_indent 0 -\math_numbering_side default -\quotes_style english -\dynamic_quotes 0 -\papercolumns 1 -\papersides 1 -\paperpagestyle default -\tracking_changes false -\output_changes false -\html_math_output 0 -\html_css_as_file 0 -\html_be_strict false -\end_header - -\begin_body - -\begin_layout Title -EEE3037 Nanotechnology Coursework -\end_layout - -\begin_layout Standard -\align center -6420013 -\end_layout - -\begin_layout Section -Quantum Engineering Design -\end_layout - -\begin_layout Subsection -Structure Design -\end_layout - -\begin_layout Subsection -Probability Plot -\end_layout - -\begin_layout Subsection -Probability Intervals -\end_layout - -\begin_layout Standard -\begin_inset Newpage pagebreak -\end_inset - - -\end_layout - -\begin_layout Section -Application of Nanomaterials -\end_layout - -\begin_layout Standard -\begin_inset Newpage pagebreak -\end_inset - - -\end_layout - -\end_body -\end_document diff --git a/coursework.pdf b/coursework.pdf index b613709..27dc7bf 100644 Binary files a/coursework.pdf and b/coursework.pdf differ diff --git a/references.bib b/references.bib new file mode 100644 index 0000000..9b3ffa6 --- /dev/null +++ b/references.bib @@ -0,0 +1,15 @@ +@article{ieee_s6824198, +abstract = "

Quantum well infrared photodetectors (QWIPs) are known for their stability, high pixel-to-pixel uniformity, and high-pixel operability, which are essential for large area imaging arrays. In this paper, we discuss the initial demonstration of QWIP devices, and the many years of progress that propelled this technology toward the demonstration of large format focal plane arrays. In addition, we present some potential applications of this technology in science and medicine.

", +author = "Gunapala, Sarath D and Bandara, Sumith V and Liu, John K and Mumolo, Jason M and Rafol, Sir B and Ting, David Z and Soibel, Alexander and Hill, Cory", +issn = "1077-260X", +journal = "IEEE Journal of Selected Topics in Quantum Electronics", +keywords = "Detectors ; Noise ; Gallium Arsenide ; Absorption ; Cameras ; Dark Current ; Engineering ; Physics", +language = "eng", +number = "6", +pages = "154,165", +publisher = "IEEE", +title = "Quantum Well Infrared Photodetector Technology and Applications", +volume = "20", +year = "2014-11", +} +