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THE QUANTUM DOT SOLAR CELL: A PATH TO ETHICAL ENERGY
Josh Demusz ([email protected])
A DILLEMA OF ETHICAL ENERGY
Imagine a world 10 years in the future where I have
acquired a stable, well-paid job as a materials engineer at an
engineering company that focuses on developing new energy
technologies. Currently, I have been working on developing
improved technologies for a special type of photovoltaic
cell, the quantum dot solar cell, in order to increase its
efficiency, or its ability to convert sunlight to electrical
power. Although my research team’s efforts to increase the
efficiency of these solar cells have been extraordinary, no
major breakthroughs have been reached. The efficiency
levels of the solar cells remain lower than other traditional
energy sources, such as nuclear energy and fossil fuel
energy. This dearth of viable discoveries has led our
company to consider discontinuing the research and moving
the scientists and engineers working on it to a different
project in its place. This project would consist of research
into developing materials that would allow the conversion of
petroleum to electrical energy to be more efficient. While
the company does not necessarily support the usage of oil
and petroleum to produce energy, they are receiving funding
from many different fossil fuel companies to create these
technologies. I, however, believe that this would be an
ethical mistake on boundless proportions. Fossil fuel energy
has demonstrated countless times that it is detrimental to
both environmental and human health, whether from the
emission of toxic materials or more specific examples such
as oil spills [1][2]. It is not ethical to continue to support
such a hazardous energy source when solar energy has the
potential to support a growing nation while also remaining
harmless to human and environmental health. These
qualities and the high potential efficiency levels quantum dot
solar cells are capable of cause me to oppose the
discontinuation of quantum dot solar cell research in favor of
petroleum technology research.
THE SOLAR CELL: AN INTRODUCTION
TO THE QUANDARY
At this instant the sun is emitting about 1.8*10 11 MWs of
power on the earth’s surface [3]. Although this amount is
thousands of times the size of the earth’s power
consumption, only an infinitesimal fraction of this energy is
actually utilized due to the inefficiencies of today’s solar
technology. The process of capturing solar energy occurs
when photons, or particles of light, come into contact with
small devices called photovoltaic cells, or solar cells, and
excite the materials of which these cells are composed [3].
If the electrons of these materials become excited enough,
University of Pittsburgh, Swanson School of Engineering
2013-10-29
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they will break free and create an electric current, hereby
producing electricity [3]. However, during the conversion
from solar power to electrical power, energy can pass
through the solar cells, be reflected by them, or be released
as heat, accounting for efficiencies of only 10-15 percent [3].
Solar energy offers an unlimited supply of alternative
energy, as humans can only survive if the sun does, but is
not utilized since it is not as economical as petroleum or
fossil fuels. However, fossil fuels are not only in limited
supply, they are also detrimental to the environment due to
the release of greenhouse gases during their combustion,
which work to deplete the ozone layer [4]. Solar energy on
the other hand does not release byproducts as it produces
electrical energy, allowing it to have a neutral effect on the
environment. This allows it to have a harmonious
relationship with various engineering codes of ethics that is
not experienced by traditional sources of energy. One
reason for this is because solar energy will advance the
quality of human life without threatening human and
environmental health, which is a tenet found in various
engineering codes of ethics [5][6]. Solar energy offers a
sustainable, omnipresent, and eco-friendly energy supply
that can decrease the use of or completely replace traditional
energy sources, such as fossil fuels, nuclear energy, and
coal, which pose threats to not only the environment but also
to human welfare. These qualities allow solar energy to be a
more ethical option than the detrimental energy sources
listed above. Its potential to become a vital and safe energy
source has been displayed by recent developing solar
technologies such as quantum dot solar cells. However,
solar energy’s potential to allow widespread clean and stable
power can only be realized if engineers and scientists strive
to produce solar cells, such as quantum dot solar cells, that
are made with more efficient materials in order to be
competitive on an economic spectrum.
IMPROVING THE QUANTUM DOT SOLAR
CELL
As stated in Mishra and Mishra’s “Environmental
Science and Ethics”, the three ethical recommendations to
define the shape of future energy include sustainability,
efficiency, and equity [7]. Sustainability concerns the
quality and quantity of energy and the effect of existing
energy on the environment [7]. The efficiency of energy
deals with the amount of energy gained compared to the
amount lost in the process of making it. Finally, equity deals
with the costs of manufacturing and implementing solar
materials [7]. Sustainability allows the technology to be
environmentally ethical, while increased efficiency and
Josh Demusz
equity will allow the technology to become a practical and
economical option.
While solar energy is inherently
sustainable, as it allows human life to be progressed while
causing no harm to the environment, it is not inherently
efficient or inexpensive. Improving quantum dot solar cell
technology, however, could change this. With further
research and development, these three tenets can be brought
to life in the form of quantum dot solar cells.
FOSSIL FUELS: A HAZARDOUS ENERGY
SOURCE
The origins of my concerns with abandoning research
into quantum dot solar cell technology in favor of petroleum
technology are rooted in the impending impacts that fossil
fuels have on human and environmental health.
TOXIC BYPRODUCTS OF FOSSIL FUEL
COMBUSTION
A QUANTUM ALTERNATIVE TO TRADITIONAL
SOLAR CELLS
In order to produce electrical energy from fossil fuels,
they must be combusted. The combustion of these fuels,
such as crude-oil, results in the emissions of several harmful
gases, such as SO2, CO, NOX, HC, and CO2 [2]. Some of
these gases, including SO2 and NOX, are responsible for acid
rain that destroys vegetation and erodes buildings, statues,
and other structures [2]. These gases are also responsible for
urban pollution, which is caused mainly by automobile
exhaust gases [2]. The more significant effect of these
gases, however, is global climate change. Global climate
change, which is caused primarily by CO2 emission, occurs
when solar heat is trapped in the atmosphere, leading to the
increased temperature of the earth [2]. This is an important
issue because of what it represents for the future ecological
cycles of the earth. The constantly increasing global
temperature is resulting in the melting of the polar ice caps,
severe droughts in countries near the equator, and even the
gradual extinction of certain species of animals [2]. The
scale of this issue can be demonstrated by the amount of
fossil fuels that humans currently use for energy production.
A study executed by the Environmental Protection Agency
concluded that “the primary greenhouse gas emitted by
human activities in the United States was CO2, representing
approximately 83.6 percent of total greenhouse gas
emissions” and that “the largest source of CO2, and of
overall greenhouse gas emissions, was fossil fuel
combustion” [4]. This is significant because it demonstrates
that fossil fuel combustion contributes to global climate
change more than any other energy source. It also
demonstrates the catastrophic events that our planet could
experience if fossil fuels continue to be supported.
In his article on environmental ethics, Holmes Rolston
from Colorado State University stated the primary causers of
global warming live in a different generation from those that
will experience its effects [9]. This is significant because it
violates the fairness and protection of safety directives that
various engineering codes of ethics share [5][6].
It is
neither fair nor safe for an engineer to plant the seeds for a
harsh future world by supporting the usage of fossil fuel as
energy. It would, however, be both fair and safe to support
the usage of solar energy for a primary power source since it
will not lead to the future environmental complications that
global warming will produce.
Quantum mechanics is an example of technology that is
within the reach of scientists and engineers, but still needs to
be pursued in order to comprehend its many details. One of
these “details,” or the quantum dot solar cell, has been the
focus of my research for the last few years. Quantum dots,
which are microscopic nanocrystals, are produced by simple
chemical reactions that allow them to have low costs and
uncomplicated fabrications [8]. This allows quantum dot
solar cells to fulfill the equity requirement for future energy,
as their manufacturing cost is relatively low when compared
with other energy sources. While the QDSSC’s low cost and
ability to capture sunlight are impressive, its current
efficiency level forbids it from being a competitive solar
technology [8]. In fact, while QDCCS’s have higher
theoretical efficiency levels than any other solar cell, around
44 percent, today they have only reached 12 percent due to
electron loss at the electrode interfaces [8]. However,
scientists and engineers such as myself are developing new
methods for allowing these solar cells to have increased
efficiencies. One example of this is incorporating nanotubes
in the solar cell’s structure [8]. These nanotubes improve
the electron transport between the electrode interfaces,
which allows for fewer electrons to be lost and more power
to be generated [8]. Another possible solution to QDSSCs’
poor efficiency levels focuses on making the impact
ionization process, or the process where sunlight excites
electrons, faster than the cooling process in order to reduce
the amount of thermal energy lost [8]. This can be
accomplished by generating “hot carriers”, which transfer
excess kinetic energy to a thermalized hole in the cell’s
structure [8]. This allows the excess kinetic energy to be
converted to electrical power, rather than lost as heat or
sound. While quantum dot solar cells cannot currently fulfill
the efficiency requirement of the future’s energy,
breakthroughs in nanotechnology combined with the
quantum dot’s high theoretical efficiency levels demonstrate
that they have the potential to be adequately efficient. This
potential can only be realized if engineers, including myself,
continue to discover techniques to improve their efficiency.
The technology to make solar energy the future’s ethical
energy source is within reach; it solely needs to be pursued
with greater passion.
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Josh Demusz
will shine through. This was demonstrated at the Gulf of
Mexico back in 2010 and at countless other disasters where
rigs and even ships have leaked crude oil into the
environment. Solar energy, however, does not pose threats
to human health. Since solar cells do not involve the usage
or production of any toxic materials, they are not able to
pose threats to human health. This allows solar energy to
agree with the first canon of the NSPE’s code of ethics.
Although fossil fuel energy is a relatively efficient power
source, one must ask themselves this: is efficiency worth
endangering the welfare of humans and nature alike when
cleaner options such as solar energy are available? When
writing on risk in engineering technologies, Michael S.
Pritchard, an engineering pioneer from Western Michigan
University, stated, “safety and risk go hand-in-hand. To set
standards of safety requires a determination of acceptable
risk” [11]. Based on the effects of and accidents caused by
fossil fuel energy, is it acceptable to consider it safe? In
order to choose an ethical energy source, or one that poses
no threat to the safety of humans and the environment,
engineers must stray away from fossil fuel energy. They
must consider alternative energy sources, such as solar
energy, which pose no threat human and environmental
health.
SAFETY CONCERNS OF PETROLEUM
UTILIZATION
Although fossil fuels are responsible for environmental
damage when they are combusted since they produce toxic
materials such as greenhouse gases, their retrieval and
transportation can also be detrimental. An example of this is
the BP oil spill in 2010, where an explosion caused 4.9
million barrels of oil to be released into the Gulf of Mexico
[10]. This leakage caused health complications and in some
cases death for both humans and animals in the surrounding
area [10]. In high enough doses, the crude oil that leaked
into the surrounding environment can cause respiratory,
hepatic, renal, endocrine, neurologic, and hematologic
complications as well as DNA mutations [1]. This has
resulted in the sicknesses of many of the local inhabitants
and 52,000 responding workers [1]. It has also resulted in
the biomagnification of marine animals, which causes
organisms such as fish to accumulate substances, such as
crude oil, in their tissues [1]. This made it dangerous for
humans and animals to consume seafood from the Gulf of
Mexico.
The first canon of the American Society of Civil
Engineer’s Code of Ethics states that engineers should seek
opportunities to work for the protection of the environment
through the practice of sustainable development [5].
Methods such as fracking and drilling for oil violate this
tenet because they are hazardous to environmental health.
Not only does fracking and drilling for oil lead to the
utilization of greenhouse gas producing fuels, but they also
risk leaking toxins into the environment. The consumption
and absorption of these toxins cause many of the organisms
in the surrounding area to obtain various body system
complications and die [1]. This has been demonstrated in
the BP oil spill and countless other incidents. Since solar
energy is able to advance human life without endangering
the environment, it can be considered sustainable. Solar
energy is therefore in agreement with this canon. Partially
or completely replacing fossil fuels with solar energy could
reduce or extinguish the chances that accidents such as oil
spills will occur. In order to make an ethical decision
concerning using fossil fuels and petroleum or solar energy
as energy sources, engineers must also realize the risks, or
absence of risks, that they pose to the environment.
The first canon of The National Society of Professional
Engineer’s Code of Ethics states that “engineers should hold
paramount the safety, health, and welfare of the public” [6].
With this tenet in mind, is it just for engineers to continue to
support energy sources, such as fossil fuel energy, that are
perpetual threats to the safety, health, and welfare of the
public? Human nature is not perfect and should not
expected to be perfect. However, these imperfections,
whether it be miscalculations, flawed logic, or even laziness,
greatly augment the dangers of utilizing methods such as
fracking. As long as these imperfections persist, as they
naturally will, the instability attached with drilling for oil
SUSTAINABLE SOLAR ENERGY: A
VISIBLE HORIZON
Although continuing research into an area such as
quantum dot solar cells is not guaranteed to produce
groundbreaking results, it is necessary for an engineer to
continue to do so because of what he or she represents.
Engineers create technologies that will propel us into a
world that is more efficient, sustainable, and accommodating
than it previously was. It would be more convenient for one
to advocate an efficient energy source such as fossil fuels,
but how would that help to change the world and create an
advantageous future? Solar energy in its current state may
not be able to change the world, but it does have the
potential to. This potential can only be met if scientists and
engineers continue to allocate funds to research new solar
cell technologies, specifically solar cells incorporating
nanotechnology and quantum dots. Solar energy offers
clean and sustainable qualities that agree with multiple
engineering codes of ethics. This is because solar energy is
not only a sustainable energy source, since it advances the
standard of living without destroying non-replenishable
natural resources, but it is also one that protects
environmental health because it does not involve the usage
of any toxic materials [11]. However, these qualities can
only be taken advantage of if engineers, including myself,
strive to improve the efficiency of emerging solar cell
technologies. Solar energy, to me, represents a clean and
safe future while fossil fuel represents a putrid and
hazardous one. This premonition, along with the knowledge
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Josh Demusz
of how efficient quantum dot solar cells could potentially be,
causes me to unceasingly support the continuation of
quantum dot solar cell research and adamantly condemn
research to improve the efficiency of fossil fuel energy.
ACKNOWLEDGEMENTS
I extend my gratitude to the following individuals for
their contributions to my paper:
I would like to thank Anne Schwann from the Bevier
Engineering Library for helping me locate research for this
paper. Without Anne’s assistance much of the content that
is crucial to my paper would have been absent.
I would like to thank my father for introducing me to
outdoor activities, such as hiking and camping, at an early
age and insisting that I continue to participate in them even
if I resisted. This gift has allowed me to truly appreciate the
outdoors and yearn to protect it from pollution caused by
humans.
I would like to thank my mother for always pushing me
to reach my academic pinnacle while also calming me if my
academics had me overwhelmed. Even if I experience
failure, she will always support me.
REFERENCES
[1] B. Goldstein, H. Osofsky, M. Lichtveld. (2011). “The
Gulf Oil Spill”. The New England Journal of Medicine.
(Online Article). DOI:
http://dx.doi.org/10.1056/NEJMra1007197 pp. 1334-1348
[2] B. Bose. (2010). “Global Warming: Energy,
Environment, and the Impact of Power Electronics.”
Industrial Electronics Magazine. (Online Article). DOI:
10.1109/MIE.2010.935860 pp. 6-17
[3] S. Rompicherla. (2013). “Solar Energy: The Future.”
International Journal of Engineering Trends and
Technology.
(Online
Article).
http://www.ijettjournal.org/volume-4/issue-6/IJETTV4I6P156.pdf
[4] (2010). “Inventory of U.S. Greenhouse Gas Emissions
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(Online
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http://www.epa.gov/climatechange/Downloads/ghgemission
s/US-GHG-Inventory-2012-ES.pdf
[5] (2006). “American Society of Civil Engineers (ASCE)
Code of Ethics.” American Society of Civil Engineers.
(Online Code). http://www.asce.org/Ethics/Code-of-Ethics/
[6] (2005). “National Society of Professional Engineers
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[7] M. Mishra, M. Mishra. (2010). “Environmental Science
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[9] H. Rolston. (2011). “The Future of Environmental
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[10] R. Kurtz. (2013). “Oil Spill Causation and the
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[11] R. Burgess, M. Davis, M. Dyrud, J. Herkert, R.
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“Engineering Ethics: Looking Back, Looking Forward.”
Science and Engineering Ethics. (Online Article). DOI:
10.1007/s11948-012-9374-7. pp. 1395-1404
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the quantum dot solar cell: a path to ethical energy