The document discusses flexible photovoltaic technology. It provides an introduction to flexible solar cells and their advantages over rigid cells, including portability and the ability to integrate with curved surfaces. Several types of flexible solar cells are described, including crystalline silicon, amorphous silicon, CIGS, cadmium telluride, and gallium arsenide cells. The document outlines testing methods for flexible cells, including evaluating flexibility through bending and efficiency testing. Potential applications are identified like integration into vehicles, bags, and buildings. The conclusion states that flexible cells are cost-effective, portable, and can absorb large amounts of light.

1. FLEXIBLE PHOTOVOLTAIC TECHNOLOGY
Department:- Electrical Engineering
Guided By Presented By
Prof. Pooja Soni Kumud Garg
(Assistant Professor) E-3
Jodhpur Institute of Engineering &
Technology

2. OUTLINES
• Introduction
• Inroduction to Flexible Solar Cell
• Literature Survey
• Flexible Photovoltaic Technology
• Different Types Of Flexible Solar Cell
• Manufacturing Process
• Testing Method
• Advantages
• Why Flexible Solar Cell?
• Application & Value Proposition
• Conclusion
• Future Scope
• References

3. INTRODUCTION
Photovoltaics (often shortened as PV) gets its name from the process of converting light (photons)
to electricity (voltage), which is called the photovoltaic effect. This phenomenon was first exploited
in 1954 by scientists at Bell Laboratories who created a working solar cell made from silicon that
generated an electric current when exposed to sunlight. Solar cells were soon being used to power
space satellites and smaller items such as calculators and watches. Today, electricity from solar
cells has become cost competitive in many regions and photovoltaic systems are being deployed at
large scales to help power the electric grid.
Types of Solar cell
• Silicon Solar Cells
The vast majority of today's solar cells are made from silicon and offer both reasonable prices
and good efficiency (the rate at which the solar cell converts sunlight into electricity). These
cells are usually assembled into larger modules that can be installed on the roofs of residential
or commercial buildings or deployed on ground-mounted racks to create huge, utility-scale
systems.

4. • Thin-Film Solar Cells
Another commonly used photovoltaic technology is known as thin-film solar
cells because they are made from very thin layers of semiconductor material, such as
cadmium telluride or copper indium gallium diselenide. The thickness of these cell layers
is only a few micrometers—that is, several millionths of a meter.
Some types of thin-film solar cells also benefit from manufacturing techniques that
require less energy and are easier to scale-up than the manufacturing techniques
required by silicon solar cells.
• III-V Solar Cells
A third type of photovoltaic technology is named after the elements that compose
them. III-V solar cells are mainly constructed from elements in Group III—e.g., gallium
and indium—and Group V—e.g., arsenic and antimony—of the periodic table. These solar
cells are generally much more expensive to manufacture than other technologies. But
they convert sunlight into electricity at much higher efficiencies. Because of this, these
solar cells are often used on satellites, unmanned aerial vehicles, and other applications
that require a high ratio of power-to-weight.
• Next-Generation Solar Cells
Solar cell researchers at NREL and elsewhere are also pursuing many new photovoltaic
technologies—such as solar cells made from organic materials, quantum dots, and hybrid
organic-inorganic materials (also known as perovskites). These next-generation
technologies may offer lower costs, greater ease of manufacture, or other benefits.
Further research will see if these promises can be realized

5. Introduction to Flexible Solar Cell
 Mechanically flexible solar cells could drastically change the way
energy is generated in the future.
 To create a more flexible solar cell there needs to be a compromise
between thickness, mechanical resilience, and durability.
 Efforts in advancing the technology of solar cell devices have been
primarily concerned with cost and efficiency of the cells.
 High device cost and preparation required to fabricate inorganic solar
cells, which are most frequently used, have limited the overall impact
that solar energy can have.
 The most common inorganic solar cell type is made using crystalline
silicon as the semiconductor layer, which is separated into two layers
of different types, positive and negative (p and n). The semiconductor
layer of this cell is sandwiched between a top cathode and bottom
anode layer, where the be wired into a circuit.

6. This basic construction is constant for all major cell types, including CdTe,
cathode has metal connections placed on to it and the anode layer is
attached to a metal contact, so that the cell can CIGS, CIS, dye sensitized,
polymer, and perovskite cells.
The inorganic solar cells we created is a type of thin film solar cell that can
be used in mechanically flexible applications, creating further options
where solar cells can be used. Furthermore, because our cell is completely
inorganic it has increased stability.
This type of solar cells differs from silicon solar cells first in that the cell
layers are constructed using deposition, creating a thinner, lighter, and as
previously stated flexible cell.
Secondly this cell type is different because the p and n type layer are made
from different classes of material, with the p-type being organic and the n
type inorganic. This helps to create a simpler cell construction overall
which aids in creating a more flexible device.

7. Literature Survey
• They have presented an experimental investigation to study a semiconductor material used
in a PV cell and its importance in determining the efficiency of the solar cell at various
parameters such as regards to behavior with respect to temperature, weight and as well as
other parameters with which it is used and all those contribute to the deciding factor of
efficiency of the PV cell The inventor has conducted many experimental researchers to
devise improvised methods and apparatus for forming thin film layers of semiconductor
materials. The field of photovoltaics generally relates to multi-layer materials, converts sun
light directly into DC Electrical Power. The basic mechanism for this conversion is “The
Photovoltaic Effect”. Solar cells are typically configured as a co-operating sandwich of P-
Type and N-Type semiconductors, in which the NType semi conductor material (on one
side of the sandwich) exhibits an excess of electrons and the PType semiconductor material
(on the other side of the sandwich) exhibits an excess of holes each of which signifies the
absence of the an electron.

8. • Has worked on in improving the efficiency of Solar Cells. They have found that the
efficiency of the solar cell varies from 15% to 22% and innovations are being carried out by
changing the combination of semiconductor material in the PV cell and find out improved
efficiency. The inventor has analyzed the properties of semiconductor material thoroughly
and has come out with a combination of cells- cascaded cell, permits achieving more than
overall efficiency of 23%. Up to the present time it has been proposed to use either
Germanium or Gallium Arsenide as the substrate for solar cell in which the principal active
junction is formed of N-Type and P-Type Gallium Arsenide. Attempts are continuing at
developing solar cells that efficiently use as much of solar spectrum as possible.
• They have worked on application of circuit model for energy conversion system.The solar
energy is directly converted to electrical energy without any electrical parts by the use of
photovoltaic system. PV system is widely utilized to cater power demands of the society in
many countries.The efficacy of the PV system depends on the operation of the system
components and its performance. The efficiency of the solar system conversion technology
stands at about 15 to 25% mainly because of the conversation of DC power to AC power
through battery bands. The best way to utilize the PV System energy is to deliver it to the
AC mains directly, without battery banks. Studies on the PV system in operation reveal
that inverters contribute to 63% failure rate, modules 15% and other components 23% with
a failure occurring on an average of every 4 to 5 years. To reduce the failure rate of the PV
systems it is necessary to reduce failure rates of inverters and components of effective
performance.

9. • The authors have conducted a study on solar collecting and utilizing device and have
concluded that the efficacy of a solar energy conversion system depends on the various
parameter such as the quantum of radiation, intensity, direction, the tilt angle of the
collector, temperature etc. In case of solar collector and utilizing device the sun tracking
and beam focused radiation are of paramount importance. This device consist of
paraboloidal mirror, a sun light collector, a solar storage and conversion device and a
solar tracking equipment wherein said sun light collector compresses a light guide which
convert factual into substantially parallel light beam and deflect them in a desired
direction and a curved surface condenser mirror which receive the substantially parallel
light beams reflected from the light guider and converting them into a solar storage and
conversion.
• They have investigated on the concentrating solar energy receivers. In their study they
have commented that the solar collectors can be classified into focusing type
(concentrating type) and Non – focusing type (non-concentrating type). The inventor has
designed the concentrating type solar energy receiver comprising a primary parabolic
reflector having a centre and a high reflective surface on a concave side of the reflector
and having a fixed axis extending from the concave side of the reflector and passing
through a fixed point of the primary parabolic reflector and a conversion module having a
reception surface. Non concentrating type solar collecting devices intercept parallel un-
concentrated rays of the sun with an array of photovoltaic cells. The output is the direct
function of array.

10. • They have worked on Optimum Collector Tilt Angle for low latitudes. There are many
factors that affect the solar radiations falling on the earth. Some of the factors that affect
the intensity of the extra terrestrial solar radiation on the earth’s horizontal and tilted
surfaces are clouds, dusts and shades. In designing the solar equipment the designer has to
pay more attention towards harnessing the insolation to the optimum level for effective
performance of the equipment. Determination of the tilt angle at lower latitudes is one such
effort for a country like Nigeria.

11. Flexible Photovoltaic Technology
Construction of Flexible Solar Cell:-

12. Different Types of Flexible Solar Cell
1)Crystalline Silicon Cells:-
• Crystalline silicon cells make up 90% of the solar panels that exist in the world
today.
• Within the distinction of crystalline cells there are two types, which are
monocrystalline and polycrystalline.
• Monocrystalline cells are formed into a single crystal from ingots and have
efficiencies ranging from 15%- 20%.
• Polycrystalline panels are simpler to manufacture they also have low efficiencies,
ranging from 13%-16%. On top of being more efficient, monocrystalline panels are
also more space efficient, longer lasting when compared with other types of cells,
and more efficient in higher temperatures. The last type of silicon cell is amorphous,
which while being the least common silicon panel type, is most suitable for thin
filmed flexible panels.
Figure1:- Crystalline Silicon Cell

13. 2) Amorphous Silicon Solar Cell:-
Along with CdTe PV cells are the most developed and widely known thin - film solar cells.
Amorphous silicon can be deposited on cheap and very large substrates ( up to 5.7 m² of glass )
based on continuous deposition techniques, thus considerably reducing manufacturing costs. A
Companies are also developing light, flexible A-Si modules perfectly suitable for flat and curved
surfaces, amorphous silicon module efficiencies are in the range 4% to 8%. Very small cells at
laboratory level may reach efficiencies of 12.2%.
Advantage:-
The advantage of the µc - Si layer is that it absorbs more light from the red and near infrared
part of the light spectrum, thus increasing the efficiency by up to 10%. The thickness of the µc -
Si layer is in the order of 3 µm and makes the cells thicker and more stable. The current
deposition techniques enable the production of multi-junction thin-films up to 1.4 m².
Figure2:- Amorphous Solar Cell

14. 3) Copper-Indium-Selenide (CIS) and Copper-
Indium Gallium-Diselenide (CIGS)
(CIGS) PV cells offer the highest efficiencies of all thin-film PV technologies. CIS solar cell
production has been successfully commercialized by many firms as shown in Fig. 8.
Current module efficiencies are in the range of 7% to 16%, but efficiencies of up to 20.3%
have been achieved in the laboratory, close to that of C-Si cells [14]. The race is now on
to Increase the efficiency of commercial modules. CIGS producer Solar Frontier has
reached an annual Production capacity of 1 GW (Bank Sarasin, 2010). on the one hand, the
CIGS module has the advantage of a low static load thanks to its light cells, while it also
has the ability to absorb direct and indirect sunlight and is therefore suitable for use on
flat roofs and in winter.
Figure3:- Copper Indium Salenide Solar Cell

15. 4) Cadmium Telluride Thin-Film Solar Cells
Cadmium telluride thin-film solar cells are the most common type available. They are
less expensive than the more standard silicon thin-film cells. Cadmium telluride thin-
films have a peak recorded efficiency of more than 22.1 percent (the percentage of
photons hitting the surface of the cell that are transformed into an electric current).
By 2014 cadmium telluride thin-film technologies had the smallest carbon
footprint and quickest payback time of any thin-film solar cell technology on the
market (payback time being the time it takes for the solar panel’s electricity
generation to cover the cost of purchase and installation).
Figure4:- Cadmium Telluride Cell

16. 5) Gallium Arsenide (GaAs) Thin-Film Solar Cells
Gallium arsenide (GaAs) thin-film solar cells have reached nearly 30 percent
efficiency in laboratory environments, but they are very expensive to manufacture.
Cost has been a major factor in limiting the market for GaAs solar cells; their main
use has been for spacecraft and satellites.
Figure5:- Gallium Arsenide Solar Cell

19. 1. Flexibility:-
The flexibility of the cell is important as a flexible cell is only
good if it can be repeated and does not greatly affect the cell
performance. To test flexibility, the final cell and each individual
layer will be bent
at a fixed radius. We will bend the cell for several cycles and use
a Scanning Electron Microscope(SEM)
to determine if any nano-level deformation has occurred.
Electrical resistance of certain layers will also be
compared before and after bending.
Testing Methods

20. 2. Efficiency:-
We will perform normal solar cell efficiency tests, observing efficiency
at sun and determining short circuit current and open circuit voltage.
The efficiency will also be tested again after the panel has been bent
to its ultimate radius, and again after it has undergone cyclic loading.
In this way, we can see if flexing has any effect on long term
efficiency, possibly indicating deformation as well. Comparing
efficiencies between low temperature and high temperature annealed
cells will also be done.

21. Advantages
• Flexible solar panels are much lighter than convential
solar panels, which makes them suitable for different
applications. Flexible solar panels can be folded or rolled
up, which makes them portable.
• As the panels can be glued on the roof, there’s no need
for mounting racks, which makes the installation more
cost effective.
• The major advantage of the flexibility is that these
panels can integrated with all kind of shapes. Flexible
solar panels can easily take the form of a car roof or can
be glued on a metal roof. The strength of this product lies
in the multiple integration possibilities.

22. WHY FLEXIBLE SOLAR PANEL?
• A large amount of light can be absorbed with a small amount of
organic materials
• Cost effective
• Formed on plastic, paper
• Highly flexible,portable and light weight
• Capable of producing voltages exceeding than 50V at normal lighting
conditions.
• Uses vapor deposition technique so it is easier to manufacture on
ordinary paper to be flexible.

23. Application
• Satelight
• Carry Bag
• As flexible solar panels are lightweight and portable, they’re also useful for
integration with power camping equipment, field communication radios and GPS
systems.
• The printable cells will have an even wider scope of applications, because all kinds
of materials can be covered with solar cells. From wall paper, to curtains, these
printable cells can change the way solar cells are applied.
• A good example is the solar roof of the Fisker Karma. The integrated flexible
solar panel is perfectly curved along the roof of the car.

24. Value Proposition

27. 
Conclusion
Due to highly thin, flexible and light weight ti is
portable. Due to large amount of absorption of
light it gives maximum energy.
It is cost effective because it uses paper or thin
plastic for base material.
It’s efficiency, physical structure and
performance is more better than conventional
solid solar panel.

28. Future Scope
• The steps taken to create a solar cell where the main goal is flexibility, rather
than efficiency or cost.
• The general construction of the cell will be an inorganic hybrid heterojunction
solar cell, where the basic layering of the cell will be
(PET/Glass)/ITO/TiO2/Sb2S3/CuSCN/(Au/Pd ).
• In this study will center around the effects that cell layers have on flexibility and
efficiency, by modifying the ZnO layer and changing what is used as the n-type
semiconductor: namely; Antimony Sulfide, or Sb2S3.
• The ZnO layer will be constructed of nanowires, and we will investigate the effect
of changing the wire concentration, shape, length, and thickness. Both the
inorganic n-type semiconductor, Sb2S3, as well as the p-type semiconductor,
CuCSN, will be altered by tuning the morphology, ratio of the p and n-type layers,
and thickness.
• Fatigue and bending tests will be applied to each cell, to observe the effect of
modifications to the structures flexibility.
• Traditional efficiency tests will also be applied before and after bending.
• Lastly given appropriate time and sufficient testing of the individual cells,
mechanical design ideas will be applied to the structure of the solar panel to
investigate covering larger areas while still maintaining flexibility and good
efficiency.

29. Reference
• Britt; Jeffery s. (tucswon.AZ) Wiedeman; Scott (Tucson.AZ) (2012), “Apparatus and Methods for
Manufacturing thin-film Solar cells”, patent paper, Application No: 12/424,505.
• 2. Ho; Frank. (Yorba Linda, CA) Yeh; Milton Y (Santa Monica, CA); (1995), “High Efficiency
MultiJunction Solar Cell”, patent paper, Application No: 08/149,052.
• Nataraj Pandiarajan, Rama Badran, Rama Prabha and Ranganathan; (2012),“Application of Circuit
Model for Photovoltaic Energy Conversion Systems”, Journal “International Journal of Photo
Energy” 2012issue.
• Zhao; Xiaofeng (Guangdong, CN) (2009) ,“Solar Collecting and Utilizing Device”, patent
paper,Application No: 10/570,887.
• Bareis; Bernard F (Plano,TX) and Goei; E Esmond T. (Dublin, CA); (2004), “Concentrating Solar
Energy Receiver”, patent paper , Application No: 10/217,861.
• Coc Oko and S.N Nanchi; (20012)“Optimum Collector Tilt Angles for Low Latitudes”, Journal “The
Open Renewable Energy” 2012 issue.
• https://www.slideshare.net/siroddeo/flexible-solar-panel-45636157.
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deposition temperature on CdS thin films for CIGS solar cells applications. Journal of Materials
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application/.

30. Thank you!