proof read part 1, added design drawing

This commit is contained in:
aj 2019-11-12 11:43:05 +00:00
parent 7a3bb3e3b3
commit 0f88146af5
4 changed files with 138 additions and 37 deletions

View File

@ -140,7 +140,7 @@ f=\frac{c}{\lambda}
\end_layout
\begin_layout Standard
In order to find the
Therefore in order to find the
\begin_inset Formula $E$
\end_inset
@ -172,14 +172,15 @@ Returning to the specifications, this allows 1.55μm to be expressed as 1.28x10
\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
This energy value will be the same as the total interband transition for
the well from the first confined hole energy level to the first confined
electron enery level,
\end_layout
\begin_layout Standard
\begin_inset Formula
\begin{equation}
\varSigma E_{g}=E_{1h}+E_{g}+E_{1e}\thickapprox0.8eV\label{eq:Energy-Gap-Sum}
E_{g,transition}=E_{1h}+E_{g}+E_{1e}\thickapprox0.8\unit{eV}\label{eq:Energy-Gap-Sum}
\end{equation}
\end_inset
@ -221,7 +222,7 @@ status open
\begin_layout Plain Layout
Band structure of an AlGaAs/GaAs/AlGaAs quantum well including discrete
energy levels
confined energy levels
\begin_inset CommandInset citation
LatexCommand cite
key "ieee_s6824198"
@ -253,18 +254,18 @@ name "fig:Well-Band-structure"
\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
should be the dominant term in this equation and as such when 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.
Ternary alloys were investigated in order to allow precise control over
the lattice constants and band gap by varying the composition ratio.
\end_layout
\begin_layout Standard
indium gallium arsenide (In
Indium gallium arsenide (In
\begin_inset script subscript
\begin_layout Plain Layout
@ -327,7 +328,7 @@ Lattice matching is the process of ensuring that two crystalline structures
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.
which ultimately negatively affect it's electronic properties.
\end_layout
\begin_layout Standard
@ -487,7 +488,7 @@ name "tab:Lattice-constants"
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 finding the weighted average the individual lattice constants
solution by finding the weighted average of the individual lattice constants
by composition ratio and is given by:
\end_layout
@ -742,8 +743,8 @@ Width Calculation
\begin_layout Standard
Having found two materials that are lattice matched with a suitable band
gap value, the final calculation is that of the quantum well width.
In order to calculate this value, the equation for energy levels within
an infinite quantum well will be used,
In order to calculate this value, the equation for confined energy levels
within an infinite quantum well will be used,
\end_layout
\begin_layout Standard
@ -787,7 +788,7 @@ noprefix "false"
\begin_layout Standard
\begin_inset Formula
\[
\varSigma E_{g}=0.8\unit{eV}=E_{1h}+E_{g}+E_{1e}=\frac{1^{2}\pi^{2}\text{\emph{ħ}}^{2}}{2m_{h}^{*}L^{2}}+E_{g}+\frac{1^{2}\pi^{2}\text{\emph{ħ}}^{2}}{2m_{e}^{*}L^{2}}
E_{g,transition}=0.8\unit{eV}=E_{1h}+E_{g,InGaAs}+E_{1e}=\frac{1^{2}\pi^{2}\text{\emph{ħ}}^{2}}{2m_{h}^{*}L^{2}}+E_{g,InGaAs}+\frac{1^{2}\pi^{2}\text{\emph{ħ}}^{2}}{2m_{e}^{*}L^{2}}
\]
\end_inset
@ -797,16 +798,16 @@ noprefix "false"
\begin_layout Standard
With the experimentally determined value for
\begin_inset Formula $E_{g}$
\begin_inset Formula $E_{g,,InGaAs}$
\end_inset
this equation can be condensed to,
this equation becomes
\end_layout
\begin_layout Standard
\begin_inset Formula
\[
0.8\unit{eV}=\frac{\pi^{2}\text{\emph{ħ}}^{2}}{2m_{h}^{*}L^{2}}+0.75+\frac{\pi^{2}\text{\emph{ħ}}^{2}}{2m_{e}^{*}L^{2}}
0.8\unit{eV}=\frac{\pi^{2}\text{\emph{ħ}}^{2}}{2m_{h}^{*}L^{2}}+0.75\unit{eV}+\frac{\pi^{2}\text{\emph{ħ}}^{2}}{2m_{e}^{*}L^{2}}
\]
\end_inset
@ -1064,7 +1065,7 @@ which reduces to a well length of 14.87nm.
\end_layout
\begin_layout Subsection
Energy Level Calculations
Confined Energy Level Calculations
\end_layout
\begin_layout Standard
@ -1113,8 +1114,8 @@ E_{1e}=6.65\times10^{-21}\unit{J}=0.041\unit{eV}
\end_layout
\begin_layout Standard
This equation shows that energy values are proportional to the square of
This equation shows that confiend energy level values are proportional to
the square of
\begin_inset Formula $n$
\end_inset
@ -1198,6 +1199,63 @@ E_{2h}=5.45\times10^{-21}\unit{J}=0.034\unit{eV}
\end_inset
\end_layout
\begin_layout Standard
With the dimensions and first confined energy levels calculated, the final
design for the quantum well can be seen in figure
\begin_inset CommandInset ref
LatexCommand ref
reference "fig:quantum-well-design"
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 well-design.png
lyxscale 30
width 85col%
\end_inset
\end_layout
\begin_layout Plain Layout
\begin_inset Caption Standard
\begin_layout Plain Layout
InP/InGaAs/InP quantum well design
\begin_inset CommandInset label
LatexCommand label
name "fig:quantum-well-design"
\end_inset
\end_layout
\end_inset
\end_layout
\end_inset
\end_layout
\begin_layout Section
@ -1239,7 +1297,7 @@ with
\end_layout
\begin_layout Standard
Where
Here
\begin_inset Formula $A$
\end_inset
@ -1337,6 +1395,17 @@ noprefix "false"
\end_inset
has been set to 1 for the ground state.
This function for the first excited state can be seen in figure
\begin_inset CommandInset ref
LatexCommand ref
reference "fig:Probability-plot-n-2"
plural "false"
caps "false"
noprefix "false"
\end_inset
.
\end_layout
\begin_layout Standard
@ -1350,7 +1419,7 @@ status open
\begin_inset Graphics
filename probability-plot.png
lyxscale 30
width 100col%
width 75col%
\end_inset
@ -1396,7 +1465,7 @@ status open
\begin_inset Graphics
filename probability-plot-with-n-2.png
lyxscale 30
width 100col%
width 75col%
\end_inset
@ -1461,7 +1530,16 @@ noprefix "false"
\end_inset
gives the final probability function for the entire well:
gives the final probability function for a distance across the well from
\begin_inset Formula $x=0$
\end_inset
to
\begin_inset Formula $x=x_{0}$
\end_inset
:
\end_layout
\begin_layout Standard
@ -1476,15 +1554,7 @@ P\left(0\leq x\leq x_{0}\right)=\frac{1}{L}\left(x_{0}-\frac{L}{2n\pi}\sin\left(
\end_layout
\begin_layout Standard
Where
\begin_inset Formula $x_{0}$
\end_inset
is an arbitrary distance across the well.
\end_layout
\begin_layout Standard
For an interval across the well, this becomes:
For an arbitrary interval across the well, this becomes:
\end_layout
\begin_layout Standard
@ -1498,6 +1568,37 @@ P\left(a\leq x\leq b\right)=\frac{1}{L}\left(\left(b-a\right)-\frac{L}{2n\pi}\le
\end_layout
\begin_layout Standard
This equation can be utilised in order to find the probability of finding
the electron between
\begin_inset Formula $2\unit{nm}$
\end_inset
and
\begin_inset Formula $4\unit{nm}$
\end_inset
and between
\begin_inset Formula $6\unit{nm}$
\end_inset
and
\begin_inset Formula $8\unit{nm}$
\end_inset
, the intervals for which can be seen plotted in figure
\begin_inset CommandInset ref
LatexCommand ref
reference "fig:Probability-plot-with-bounds"
plural "false"
caps "false"
noprefix "false"
\end_inset
.
\end_layout
\begin_layout Standard
\begin_inset Float figure
wide false
@ -1509,7 +1610,7 @@ status open
\begin_inset Graphics
filename probability-plot-with-bounds.png
lyxscale 30
width 100col%
width 75col%
\end_inset
@ -1576,7 +1677,7 @@ P\left(2\unit{nm}\leq x\leq4\unit{nm}\right)=\frac{1}{14.87\unit{nm}}\left(2\uni
\begin_layout Standard
\begin_inset Formula
\[
P\left(2\unit{nm}\leq x\leq4\unit{nm}\right)\thickapprox0.132
P\left(2\unit{nm}\leq x\leq4\unit{nm}\right)\thickapprox0.0955
\]
\end_inset
@ -1620,7 +1721,7 @@ P\left(6\unit{nm}\leq x\leq8\unit{nm}\right)=\frac{1}{14.87\unit{nm}}\left(2\uni
\begin_layout Standard
\begin_inset Formula
\[
P\left(6\unit{nm}\leq x\leq8\unit{nm}\right)\thickapprox0.132
P\left(6\unit{nm}\leq x\leq8\unit{nm}\right)\thickapprox0.263
\]
\end_inset

Binary file not shown.

BIN
well-design.png Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 70 KiB

BIN
well-diagram.odg Normal file

Binary file not shown.