Solar Cells and Quantum Dots

Running head: SOLAR CELLS AND QUANTUM DOTS
Solar Cells and Quantum Dots
Name of the Student
Name of the University
Author Note

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SOLAR CELLS AND QUANTUM DOTS
Table of Contents
Introduction......................................................................................................................................2
Discussion........................................................................................................................................2
Energy transfer in the semiconductor..........................................................................................2
A general overview of solar energy.............................................................................................2
Quantum dot solar cells...............................................................................................................4
Core-shell quantum dots..............................................................................................................6
Solar cells.....................................................................................................................................8
Quantum confinement.................................................................................................................9
Self-assembled photonic structures for light localization..........................................................13
Ordered structure “Photonic crystals”.......................................................................................14
Photo electrochemistry at Q.D.s sensitized films......................................................................14
Quenching of fluorescence peak of cdte qds with selenide and electrolyte to the qds part.......15
Conclusion.....................................................................................................................................17

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Introduction
Semiconductors are the materials that have their levels of resistance between that of a conductor
as well as an insulator. By the introduction of the impurities into the lattice of the crystals, the
modification of the conductivity of the semiconductors can be done. These are common and are
found in all electronic devices. This report deals with an overview of the solar energy along with
the kinds of solar cells along with all the three generations of the solar cells, along with their
percentages of efficiencies. The concept of the quantum dot solar cells has also been discussed
along with the core-shell of quantum dots and the quantum confinement is also present. The
photo electrochemistry at sensitized films are also mentioned in this report.
Basically solar cell is any kind of device that helps in the conversion of light energy to
the electrical energy by the effect that is photovoltaic in nature as photovoltaics is the method
involved for converting the sunlight in the form of electricity directly with utilization of solar
cells which is rapidly growing nowadays and is becoming increasingly important day by day.
Discussion
Energy transfer in the semiconductor
Transfer of Energy refers to the energy transformation, involves the transfer of heat, collision
electric power transmission and many more. The removal of energy in the semiconductor is
significant.
A general overview of solar energy
The Solar Energy is very advantageous in many ways, one of the reasons is that all the
radioactive, as well as chemical by-products of the thermonuclear reactions which creates

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pollution in the sun, are retained itself, and only the transmission of the radiant energy that is
pure takes place on the earth. Solar Energy can be considered as non-polluting in nature under
the above mentioned conditions. The most important issue is energy production, which includes
the growth of population, quality of life as well as fair energy distribution.
Nowadays, energy is obtained primarily mainly with the help of the fossil fuels that are
non-renewable like fuel, natural gases, oil. It has been indicated that if the similar trend of energy
consumption is continued, in 2035 the contribution of fossil fuels to the needs of the world will
highly increase. A dynamic process of transition of energy is initiated due to the depletion of the
natural resources and the necessity of the protection of the environment. Consumption of global
Energy is strongly dependent on fossil fuels is now moving towards a system which is firmly
based on renewable resources.
On a worldwide scale, huge methods are being implemented for renewable energy
development. The utilization of the semiconductor nanoparticles which are situated in these thin
films is fully expanded along with the utilization of the huge bandgap semiconductors due to the
usage of titanium mostly. When the U.V. light source irradiates the nanoparticles of titanium
dioxide, the excited electrons are transferred to the conduction band from the valence band.

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SOLAR CELLS AND QUANTUM DOTS
Figure 1: The electricity-related federal subsidies in the fiscal year 2016 for selected
technologies, according to the Institute for Energy Research [2]
From the above mentioned diagram, it can be observed that the largest electricity-related federal
energy since the biofuels have received the largest share, which is of 37% as it can be seen the
form above mentioned figure1.
In this type of sector, nowadays there are various numbers of parameters under the context of
improvement like the efficiency of the conversion, lower cost of production and last but not the
least is the reduced impact on the environment. Nowadays, high levels of interest are present in
these types of research is present, and the main focus of it is on the technologies with thin films
as well as the solar cells. The utilization of the nanoparticles of the semiconductor in these thin
films is present in a full-length expansion along with the use of the semiconductors with massive
band gaps because of titanium having most of the usage.
When U.V. light source irradiates the nanoparticles of the titanium dioxide, the transfer of the
excited electrons to the conduction band as well as the valence band to substrate the
semiconductor which is to be held in turn allowing the production of the photocurrent.

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SOLAR CELLS AND QUANTUM DOTS
Quantum dot solar cells
A QDSC or quantum dot solar cell is a design of the solar cell which utilizes the quantum
dots in the form of photovoltaic material that can be absorbed. It takes an initiative for replacing
the materials that are bulk like cadmium telluride (CdTe), silicon and Copper indium gallium
selenide (CIGS). The quantum dots consists of band gap which are tunable across a massive
range of levels of energy by the method of altering their size. The band gap is constant by the
selection of the materials in context of the bulk materials. The quantum dots is made more
attractive by this property for the solar cells with multiple junctions where various kinds of
materials are utilized for the improvement of the efficiency by the process of harvesting of the
multiple parts of the solar spectrum. Basically the quantum dots are the particles which are
semiconducting in nature.
This dichotomy has motivated investigations of a novel protocols to localize and increase
light energy conversion by enhancing the absorbance of ultra-thin films; photonic crystals [7][8]
[9][10][11][12][13][14][15][16][17] and plasmonic particles [18][7][8][9][10][11][12][13][14]
[15][16][17] [19] are examples of systems that have been explored for this purpose. Investigation
of the novel protocols is motivated by the dichotomy for increasing as well as localizing the
conversion of the energy of light by the process of enhancement of the absorbance of those films
that are ultra-thin in nature.
The common examples of such kind of systems which have been explored for this
purpose are plasmonic particles as well as photonic crystals. Quantum dots (Q.D.) are one of the
emerging materials[20][21][22][23][24].
The quantum dots which can be also be abbreviated in the form of Q.D. are one of such
materials which are emerging and which have been studied for the solar cells of the third
generation because of the advantage of unique tunable electronic of it along with the theoretical