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PAPER PRESENTED BY
S.AYYUBH (III EEE)
H..MUHAMEED DEEN(IV EEE)
E-mail –[email protected]
Cell 9865998719
ABSTRACT
The race for the super power status had lead directly into many conspiracies,
thanks to the cold wars, world wars and many other annexations.. All these have not only
opened a new channel for destructive missions alone, they have also helped the nations to
gain momentum in the field of research and development. Puzzled? Well, the wars
amongst the allied nations have directly contributed to the development in science and in
order to combat the challenges posed, each country started inventing new macros. Our
paper throws light on our attempts to tap solar energy even at times when the sun is not
visible, still puzzled?? This paper in combination with our innovative ideas has portrayed
the tapping of solar energy even at dark nights. The basic concept is based on the re
tapping of the unused solar energy that gets stored in the infrared region during the
energy transfer, actually while energy transfer takes place, the quantum energy is split
into two tributaries. One is channeled to the visible spectrum, and another is channeled to
the infrared spectrum and this energy is left unnoticed. Our innovative ideas frames a
conceptual approach in combination with the nano technology to use this unnoticed form
of energy even during times when the sky is cloudy and stuff like that. This method
actually enhances the output efficiency. As you peruse the pages you’ll marvel how in
this increasingly fast paced techno-thirst world, we have taken on information
highway….
Spray-on solar
Our innovative concept is based on the framing of a plastic solar cell that can turn the
sun's power into electrical energy, even on a cloudy day. The plastic material uses
nanotechnology and contains the first solar cells able to harness the sun's invisible,
infrared rays. Plastic solar cells can actually tap energy that is five times more efficient
than current solar cell technology.
Ideology
"The sun that reaches the Earth's surface delivers 10,000 times
more energy than we consume.
If we could cover 0.1 percent of the Earth's surface with [very efficient] large-area
solar cells, we could in principle replace all of our energy habits with a source of power
which is clean and renewable."
Infrared Power
Plastic solar cells are not new. But existing materials are only able to harness the
sun's visible light. While half of the sun's power lies in the visible spectrum, the other
half lies in the infrared spectrum. The new material is the first plastic composite that is
able to harness the infrared portion. "Everything that's warm gives off some heat. Even
people and animals give off heat.
We have integrated a new platform that combines specially designed nano
particles called quantum dots with a polymer to make the plastic that can detect energy in
the infrared. With further advances and simultaneous analysis, the so called new plastic
"could allow up to 30 percent of the sun's radiant energy to be harnessed, compared to 6
percent in today's best plastic solar cells.
. Cost-Effectiveness
Ultimately, a large amount of the sun's energy could be harnessed through "solar
farms" and used to power all our energy needs. "This could potentially displace other
sources of electrical production that produce greenhouse gases, such as coal .At a current
cost of 25 to 50 cents per kilowatt-hour, solar power is significantly more expensive than
conventional electrical power for residences.
Flexible, roller-processed solar cells have the potential to turn the sun's power into a
clean, green, convenient source of energy.
Fabrication of the solar cell
The most common material used in solar cells is single crystal silicon. Solar
cells made from single crystal silicon are currently limited to about 25% efficiency
because they are most sensitive to infrared light, and radiation in this region of the
electromagnetic spectrum is relatively low in energy.
Polycrystalline ("many crystals") solar cells are made by a casting process in which
molten silicon is poured into a mould and allowed to cool, then sliced into wafers. This
process results in cells that are significantly cheaper to produce than single crystal cells,
but whose efficiency is limited to less than 20% due to internal resistance at the
boundaries of the silicon crystals.
Fig
ure -- Single
crystal solar
cells
Figure -- Amorphous solar cells
Amorphous cells are made by depositing silicon onto a glass substrate from a reactive gas
such as silane (SiH4). This type of solar cell can be applied as a thin film to low cost
substrates such as glass or plastic. Thin film cells have a number of advantages, including
easier deposition and assembly, the ability to be deposited on inexpensive substrates, the
ease of mass production, and the high suitability to large applications. Since amorphous
silicon cells have no crystal structure at all, their efficiencies are presently only about
10% due to significant internal energy losses.
Aside from the various forms of silicon, a number of other materials can also be used to
make solar cells -- gallium arsenide, copper indium diselenide and cadmium telluride to
name a few. Note that solar cells are sensitive to different wavelengths of light (i.e.,
photons of different energies) as a function of the materials they are built from.
Accordingly, some cells are better performers outdoors (i.e., optimized for sunlight),
while others are better performers indoors (optimized for fluorescent light).
Nowever, high-tech solar cells have yielded improved energy conversion
efficiency by incorporating two or more layers of different materials with different
wavelength sensitivities. Top layers are designed to absorb higher energy photons while
allowing lower energy photons through to be absorbed by the layers beneath. Double-
junction cells are commercially available to Beamers on occasion (surplus shops often
call these "spacecraft cells"). Spacecraft and other mass-sensitive applications have now
started to make use of triple-junction cells (but don't expect to find these in surplus shops
any time soon).
The fabrication of the solar cells can be farmed by introducing a nano-structured layer
(i-layer) where organic semiconductor forms a 3-dimensional p-n junction at the
molecular level into p-n junction interface of organic thin-film solar cell based on organic
semiconductor to construct a p-i-n junction expands the photovoltaic conversion layer to
enhance the efficiency of light utilization. With the p-i-n type organic thin-film solar cell,
energy conversion efficiency, 4 %, a world top level, has been achieved under the
condition of simulated solar radiation of AM1.5G. It is expected that this feat will
accelerate the implementation of plastic film solar cell characterized by lightweight and
flexibility. upgrading of light utilization efficiency by expanding the photovoltaic
conversion layer has been regarded as the key factor for improving the energy conversion
efficiency of organic thin-film solar cells.
Background
The solar photovoltaic power generation utilizing clean and inexhaustible solar
energy is expected to be the major domestic energy source in future in view of
preventing global warming. The power generation cost with prevailing silicon solar
cells is currently about 3 times as high as that of household power price, and about 6
times that of industrial power price.
There are two types of semiconductors depending upon the electric charge of
carriers: p-type with current carried by positive holes (positive charge), and n-type by
conducting electrons (negative charge). Among organic materials, there are a number of
semiconductors of either type.
Fig. 1. Augmentation of molecular p-n junction interface by introducing a
nano-structured layer (i-layer) to the p-n junction
The technique of augmenting the thickness of photovoltaic conversion layer
by forming p-i-n junction with intrinsic semiconductor layer (i-layer) added to the
p-n junction interface has been often applied to silicon or other inorganic solar cells.
The details of this technique will be described below
(1) A p-i-n junction type organic thin-film solar cell is prepared by vacuum
deposition process. The i-layer is formed by co-deposition with volume ratio
controlled at [ZnPc]:[C60] = 1:1. Thickness of three layers of organic
semiconductor is 5 nm for p-layer, 15 nm for i-layer and 30 nm for n-layer,
totaling 50 nm. An organic buffer layer is inserted between each electrode
and organic semiconductor interface for establishing good contact
Structure of p-i-n junction type organic thin-film solar cell
Organic thin-film solar cell based on organic semiconductor is a solid-state
solar cell working in the same principle as silicon solar cell, but its energy
conversion efficiency is rather poor.
The efficiency of light utilization has been improved by preparing p-i-n
junction organic thin-film solar cell with nano-structured layer (i-layer)
introduced to organic p-n junction interface to form multiple nano-p-n
junctions, to achieve 4 % efficiency, a world top level among the organic
thin-film solar cells.
Implementation of plastic film solar cells characterized by lightweight and flexibility
will be accelerated
Schematic representation of the carrier transport and carrier
generation
Innovative concept-fabrication of the smart material.
Our innovative concept has paved way one step closer to the goal of flexible,
low-cost, lightweight solar cells made of plastic.A polymer-based photovoltaic material
that can harness a part of the sun's spectrum that had previously evaded
capture.Because the polymers in plastic solar cells currently under development absorb
only visible light, they convert about 6 percent of the sun's energy into electrical power.
If the materials could harvest both the visible and infrared parts of the spectrum, plastic
solar cells might achieve up to 30 percent efficiency.When exposed to infrared rays, the
quantum dots absorbed the light and gave up electrons, generating a current.By varying
the size of the quantum dots
#Solar cell#
Made of a single layer of plastic sandwiched between two conductive
electrodes, solar cell is easy to mass-produce and costs much less to make - roughly
one-third of the cost of traditional silicon solar technology.... "We hope that
ultimately solar energy can be extensively used in the commercial sector as well as
the private sector. Solar energy is a clean alternative energy source. It's clear, given
the current energy crisis, that we need to embrace new sources of renewable energy
that are good for our planet. The price for quality traditional solar modules
typically is around three to four times more expensive than fossil fuel. While prices
have dropped, the solar module itself still represents nearly half of the total installed
cost of a traditional solar energy system.
Currently, nearly 90 percent of solar cells in the world are made from a
refined, highly purified form of silicon - the same material used in manufacturing
integrated circuits and computer chips. High demand from the computer industry
has sharply reduced the availability of quality silicon, resulting in prohibitively high
costs that rule out solar energy as an option for the average consumer.
Performance &use
An important feature of solar cells is that the voltage of the cell does not depend on
its size, and remains fairly constant with changing light intensity. However, the current in
a device is almost directly proportional to light intensity and size1. The Figure shows
example I / V curves for a single cell as a function of light input:
GRAPH
Figure-- Single-junction solar cell I/V curves
A solar cell's power output can be characterized by two numbers -- a maximum
Open Circuit Voltage (Voc, measured at zero output current) and a Short Circuit Current
(Isc, measured at zero output voltage). Remember that power can be computed via this
equation:
P = I * V
So with one term at zero these conditions (V = Voc @ I = 0; V = 0 @ I = Isc) also
represent zero power. As you might then expect, a combination of less than maximum
current and voltage can be found that maximizes the power produced. This condition is
called, not surprisingly, the "maximum power point". BEAM solar engine designs
attempt to stay at (or near) this point. The tricky part is building a design that can find the
maximum power point regardless of lighting conditions2.Note that single junction silicon
solar cells produce approximately 0.5 - 0.6 Voc, so they are usually connected together in
series to provide larger voltages. In some cases (like the Panasonic Sunceram cells),
multiple cells are built onto a single substrate in order to yield the convenience of higher
output voltage from a single package.
Some more subtle properties of solar cells also need to be accounted for in
their use. In particular, when connecting solar cells in series, care needs to be taken
to give all cells roughly equal access to light -- the weakest solar cell in series (or one
that is shaded) will determine the total current. Normally this is not an issue in
BEAM bots, and will only rear
*CONCLUSION*
This paper throws light on the fabrication of a most effective and a economical gadgets
called the palsticated solar cells.. This fabrication is made possible by the integration of
Nano technology and other innovative ideas. This paper predicts a cheap way through
which the solar energy can be tapped even during cloudy days and even at dark nights..
This is not a thesis, it’s a solid analysis and its possible and if it is given proper shape it
would create a revolution in this techno savvy, power thirst world.
REFEENCES
1.WWW.efymag.org
2.www.UNISCI.COM
3.WWW.BRIGHTSURF.COM
4.WWW.SPACEDAILY.COM