Conference Session B6
Paper 6148
Disclaimer — This paper partially fulfills a writing requirement for first year (freshman)
engineering students at the University of Pittsburgh Swanson School of Engineering. This paper
is a student, not a professional, paper. This paper is based on publicly available information and may
not be provide complete analyses of all relevant data. If this paper is used for any purpose other than
these authors’ partial fulfillment of a writing requirement for first year (freshman) engineering
students at the University of Pittsburgh Swanson School of Engineering, the user does so at
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REVISED PROPOSAL
Nicholas Evanoff, nle8@pitt.edu, Mahboobin, 4:00
Joseph Nicolosi, jdn27@pitt.edu, Mena, 4:00
USE OF MULTI-JUNCTION SOLAR CELLS WITH QUANTUM DOTS TO
IMPROVE EFFICIENCY AND PRODUCTIVITY OF SOLAR PANELS
The use of multijunction cells with
quantum dots can increase the efficiency of
solar panels and decrease production costs to
make solar energy more profitable and
provide a strong alternative to fossil fuels.
Regular solar cells convert sunlight from a
single region of the spectrum [1]. In multijunction cells, each junction absorbs sunlight
from a specific region of the sunlight
spectrum, meaning that multiple regions of
light can be absorbed and harnessed, as
opposed to just one [1]. Because these
junctions or subcells can be stacked on top
of each other, they have the potential to
absorb much more sunlight [1]. Quantum
dots can be used to adjust even further what
range of the solar spectrum is absorbed by
the multijunction solar cells so that these
cells can be even more specific as to the
range of light they are absorbing, increasing
the efficiency of the solar cells [2]. The
quantum dots make these solar cells more
efficient by making it possible for solar cells
to become even more specific in the type of
light they absorb, so the cells do not let any
light be wasted. What makes quantum dots
have the ability to change what light is
absorbed is due to their band gap. A band
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gap is an area of a solid where no electrons
can exist. The only way for them to pass
from one side of the solid to the other is if
they have enough energy to “jump” the gap
[3]. So the area of light absorbed will be
determined by the energy of the electrons in
each part of the spectrum. [3].
Using multijunction cells with
quantum dots to improve solar panels is
important to engineering because it makes
solar energy much more attractive. As of
2015, solar energy made up only 0.4% of
US energy consumption [4]. The main
reason for its lack of use as a large source of
energy is due to the sizeable numbers of
panels needed to produce large amounts of
energy [4]. By increasing the efficiency of
the solar cells, fewer panels would be
needed to produce large amounts of energy.
Money would be saved by decreasing the
amount of solar panels needed to produce
energy, and companies would be able to
install more solar panels to increase their
energy production. Solar energy would
become more attractive because it would
become much cheaper and offer a clean
energy solution to fossil fuels, which cause a
great deal of pollution to meet energy needs.
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Conference Session B6
Paper 6148
In our paper we will begin by
explaining the technology behind solar cells
and how multi-junction solar cells differ
from single solar cells. After this we will
explain the principles behind quantum dots
and how they can be used to increase the
efficiency of multi-junction solar cells. After
this we will show that by increasing the
efficiency of solar panels and solar energy, it
will make it a more profitable fuel source.
By showing it is more profitable now and
that it is attractive due to it being a clean
energy source, we will be able to make the
case that solar energy could replace fossil
fuel. We plan on using scholarly articles
and sources from the library for our
research.
REFERENCES
Ellingsons, Randy, Mathew Beard, Justin
Johnson, Pingron Yu, Olga Micic, Arthur
Nozik, and Andrew Shabaev. "Highly
Efficient Multiple Exciton Generation in
Colloidal PbSe and PbS Quantum Dots."
Nano Letters. N.p., 30 Mar. 2006. Web. 13
Dec. 2016.
Katz, Cheryl. "Will New Technologies Give
Critical Boost to Solar Power?" By Cheryl
Katz: Yale Environment 360. Yale
University, 11 Dec. 2014. Web. 13 Jan.
2016.
Nozik, A.J. "Quantum Dot Solar Cells."
Quantum Dot Solar Cells. University of
Pittsburgh, 2005. Web. 13 Jan. 2016.
TOPIC AREA: INDUSTRIAL
We believe that our paper should be
included in the industrial engineering
category at the conference. We think this
because while solar panel technology is part
of environmental or mechanical engineering,
the technology’s application in this paper
will be to improve the efficiency of solar
technology to improve profits from it and
make it able to expand as an alternate
energy. By making solar energy more
efficient it will open up a new market to
make new consumers. This will optimize the
profit for many many energy companies
which is exactly what Industrial Engineers
do.
[1] Zyga, Lisa. "Multijunction Solar Cell
Could Exceed 50% Efficiency Goal."
Multijunction Solar Cell Could Exceed 50%
Efficiency Goal. Phys.org, 20 Feb. 2013.
Web. 13 Jan. 2016.
[2] BORGHINO, DARIO. "Quantum Dot
Breakthrough Could Lead to Cheap Sprayon Solar Cells." Quantum Dot Breakthrough
Could Lead to Cheap Spray-on Solar Cells.
Giz Mag, 24
June 2014. Web. 13 Jan.
2016.
[3] Chandler, David L. "Explained:
Bandgap." MIT News. Massachusetts
Institute of Technology, 2010. Web. 13 Jan.
2016.
[4] Institute for Energy Research. "Solar IER." IER. Institute for Energy Research,
2015. Web. 28 Jan. 2016.
ANNOTATED BIBLIOGRAPHY
Beard, Mathew. "Multiple Exciton
Generation in Colloidal Silicon
Nanocrystals." Nano Letters. ASC
Publications, 24 July 2007. Web. 13 Jan.
2016.
SOURCES CONSULTED
Beard, Mathew. "Multiple Exciton
Generation in Colloidal Silicon
Nanocrystals." Nano Letters. ASC
Publications, 24 July 2007. Web. 13 Jan.
2016.
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This article, from The American Chemical
Society database, describes how multiple
exciton generation in colloidal silicon
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Conference Session B6
Paper 6148
nanocrystals make solar energy more
efficient. This article talks about the process
of the absorption of a single photon in a
nanocrytal. This allows the energy from the
photon to be passed through the crystal
structure to the electric current. We will use
this to explain the process of solar power
absorption.
importance of bandgaps to solar energy and
how they can further improve the absorption
of it.
Ellingsons, Randy, Mathew Beard, Justin
Johnson, Pingron Yu, Olga Micic, Arthur
Nozik, and Andrew Shabaev. "Highly
Efficient Multiple Exciton Generation in
Colloidal PbSe and PbS Quantum Dots."
Nano Letters. N.p., 30 Mar. 2006. Web. 13
Dec. 2016.
http://pubs.acs.org/doi/abs/10.1021/nl05026
72
BORGHINO, DARIO. "Quantum Dot
Breakthrough Could Lead to Cheap Sprayon Solar Cells." Quantum Dot Breakthrough
Could Lead to Cheap Spray-on Solar Cells.
Giz Mag, 24
June 2014. Web. 13 Jan.
2016.
http://www.gizmag.com/quantum-dot-solarcells/32478/
This article is from a journal that focuses on
nanotechnology. The article is about
findings that quantum dots can be used to
increase the efficiency of solar panels
through their quantum dots’ bandgap. This
is because in normal semiconductors, impact
ionization is inefficient due to energy
restrains. Quantum dots alleviate this
because they have a larger threshold. This
article can explain how quantum dots can
make solar panels more effective.
This article, from a scientific based
magazine, explains an experiment done by
the University of Toronto analyzing
colloidal quantum dots as they interact with
oxygen. The article talks about how using
different semiconductor within a quantum
dot can increase efficiency. It also mentions
the applications of an adjustable band gap to
optimize the energy intake. It also talks
about a spray on application of using
quantum dots.
Institute for Energy Research. "Solar IER." IER. Institute for Energy Research,
2015. Web. 28 Jan. 2016.
This article is from the Institute for Energy
Research and explains the technology
behind photovoltaic cells and
semiconductors. It then explains how solar
energy is used in the United States along
with how much of it is used compared to
other energy sources. Information from this
article will help us to show that the solar
industry has the ability to grow
tremendously using the improvements
argued for in our paper.
Chandler, David L. "Explained:
Bandgap." MIT News. Massachusetts
Institute of Technology, 2010. Web. 13 Jan.
2016.
http://news.mit.edu/2010/explainedbandgap-0723
This article, from a M.I.T research database,
explains the science behind a bandgap and
why they are important to solar energy.
Bandgaps, found in semi conductors, are
areas where electrons cannot be found. Band
gaps are what make it possible for
semiconductors to harness solar energy. This
article will be used to explain the
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Kamat, Prashant. "Boosting the Efficiency
of Quantum Dot Sensitized Solar Cells
through Modulation of Interfacial Charge
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Conference Session B6
Paper 6148
Transfer." - Accounts of Chemical Research
(ACS Publications). American Chemical
Society, 11 Apr. 2012. Web. 28 Jan. 2016.
http://phys.org/news/2013-02-multijunctionsolar-cell-efficiency-goal.html
This article, from a research and technology
based website, describes how modern
inventions breakthroughs in multi-junction
cells are making solar energy more efficient.
Throughout the article it talks about the
benefits of using a large band gap,
increasing the lattice energy difference
within the cell, and the effects of using an
anti-reflecting coating. The article goes on
back up its finding listing experiments from
various reputable universities.
This article from the American Chemical
Society talks about the increasing the
Efficiency of Quantum Dot Sensitized Solar
Cells through Modulation of Interfacial
Charge Transfer. This article goes on to talk
about how semiconductor nanocrystals and
metal chalcogenides are helpful in
maximizing energy intake. The article talks
about how the change in band gap
corresponds directly to the semiconductor in
use.
Katz, Cheryl. "Will New Technologies Give
Critical Boost to Solar Power?" By Cheryl
Katz: Yale Environment 360. Yale
University, 11 Dec. 2014. Web. 13 Jan.
2016.
Nozik, A.J. "Quantum Dot Solar Cells."
Quantum Dot Solar Cells. University of
Pittsburgh, 2005. Web. 13 Jan. 2016.
http://e360.yale.edu/feature/will_new_techn
ologies_give_critical_boost_to_solar_power
/2832/
This article, from a Yale University website,
explains the benefits of using a mulitjunction that are split into layers. The article
describes the cell is composed of different
semiconductors such as perovskite and
gallium-arsenide that maximize energy
consumption by using a series of quantum
dots. Is also talks about tunable
semiconductors that allow the solar cell to
absorb energy from all of the light spectrum.
Zyga, Lisa. "Multijunction Solar Cell Could
Exceed 50% Efficiency Goal." Multijunction
Solar Cell Could Exceed 50% Efficiency
Goal. Phys.org, 20 Feb. 2013. Web. 13 Jan.
2016.
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