Solar cells convert sunlight directly into electricity through the photovoltaic effect. They have increased in efficiency since first being developed in 1954 at Bell Laboratories. There are various types of solar cells including first generation crystalline silicon cells, thin film second generation technologies like amorphous silicon and CIGS, and emerging third generation technologies. Solar cells provide clean renewable energy but have disadvantages related to initial cost and land requirements.

1. SOLAR CELLS
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2. INTRODUCTION
• Earth receives an incredible supply of solar energy.
• sun is a fusion reactor that has been burning over 4 billion years.
• provides enough energy in 1 minute to supply the world's energy
needs for 1 year.
• Solar energy- free, inexhaustible resource, yet harnessing it is a
relatively new idea.
• biggest jumps in efficiency came with the advent of the
transistor and accompanying semiconductor technology.
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3. WHAT IS SOLAR CELL?
• solar cell/photovoltaic cell - electrical device
that converts the energy of light directly into electricity by
the photovoltaic effect, which is a physical and chemical
phenomenon.
• a form of photoelectric cell, defined as a device whose electrical
characteristics (current,voltage, or resistance) vary when exposed to
light.
• Solar cells are the building blocks of solar panels.
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4. HISTORY OF SOLAR CELL
• “Photo” = “light” (Greek meaning )
“voltaic”=“Volta” (name of Italian physicist)
• The PHOTOELECTRIC EFFECT- French physicist A.E
BECQUEREL(1839)
• ALBERT EINSTEIN explained the photoelectric effect (1905)
He got the Nobel prize in physics in 1921
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5. • The modern photovoltaic cell was developed in 1954 at BELL
LABORATORIES
• The highly efficient solar cell was first developed by DARYL
CHAPIN,CALVIN SOUTHER FULLER and GERALD PEARSON in
1954 using a diffused silicon p-n junction
• Solar cells were first used in Vanguard I satelite,launched in 1958
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6. ADVANTAGES OF PHOTOVOLTAIC
SOLAR POWER
• a promising renewable energy sources in the world.
• non-polluting
• no moving parts that could break down
• requires little maintenance and no supervision
• life of 20-30 years with low running costs.
• remote areas can easily produce their own supply of electricity by
constructing as small or as large of a system as needed.
• more practical than the extension of expensive power lines into
remote areas.
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7. DISADVANTAGES OF SOLAR CELLS
• Initial cost
• Large areas of land to achieve average efficiency
• Air pollution and weather affects efficiency of cells.
• Silicon used is expensive
• Electricity generated only during day time.
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8. Working of solar cells
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9. CLASSIFICATION OF SOLAR CELLS
FIRST GENERATION SOLAR CELLS
• conventional/traditional/ wafer-based cells
• made of crystalline silicon, the commercially predominant PV technology,
includes materials such as polysilicon and monocrystalline silicon.
• made from a single silicon crystal (mono-crystalline), or
cut from a block of silicon that is made up of many crystals(multi-crystalline).
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10. SECOND GENERATION SOLAR CELLS
• thin film solar cells
• include amorphous silicon, CdTe and CIGS cells
• Less expensive to produce than traditional silicon solar cells
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11. THIRD GENERATION SOLAR CELLS
• number of thin-film technologies often described as emerging
photovoltaics
• most of them have not yet been commercially applied
• still in the research or development phase.
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12. TYPES OF SOLAR CELLS
1) Amorphous Silicon Solar Cell (A-Si)
2) Biohydrid Solar Cell
3) Concentrated PV Cell(CVP and HCVP)
4) Copper Indium Gallium Selenide solar cells
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13. AMORPHOUS SILICON SOLAR CELL
• non-crystalline form of silicon.
• used in pocket calculators, also powers some private homes, buildings, and remote
facilities.
• formed by vapor-depositing a thin layer of silicon material – about 1 micrometer
thick – on a substrate material such as glass or metal.
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14. • Can also be deposited at very low temperatures (750 C).
• In its simplest form, the cell structure has a single sequence of p-i-n layers.
• Better stability requires the use of a thinner layers -> increases electric field
strength across materials -> reduces light absorption -> reduces cell efficiency .
• To solve, triple layer devices that contain p-i-n cells stacked one on top of other.
• Triple layer system is to capture light from full solar spectrum.
• principal advantage- lower manufacturing costs, makes these cells very cost
competitive.
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15. AMORPHOUS SILICON SOLAR CELL
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16. BIOHYDRID SOLAR CELL
• combination of organic matter (photosystem I) and inorganic matter.
• recreates process of photosynthesis to obtain a greater efficiency in
solar energy conversion.
• Multiple layers of photosystem I gather photonic energy > converted
to chemical energy > creates current > goes through the cell.
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• injected photosystem I complexes introduced and gathered for several
days in gold layer.
• team from Vanderbilt University began conducting research
• resulted in a greatly improved electrical current (1000 times greater
than others)

18. BIOHYDRID SOLAR CELL
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19. CONCENTRATED PV CELL
(hcvp and cvp)
• CPV converts light energy into electrical energy
• advanced optical system used to focus large area of sunlight onto each cell for
maximum efficiency.
• Different CPV designs exists, differentiated by the concentration factor.
low-concentration (LCPV)
 high concentration (HCPV).
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20. • lenses and curved mirrors used to focus sunlight onto small,but highly
efficient,multi-junction (MJ) solar cells.
• also has solar trackers and a cooling system to further increase their
efficiency.
• Efficiency level greater than 41%
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21. CPV SOLAR CELL
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22. Copper indium gallium selenide solar
cells [cigs]
• thin film solar cell used.
• manufactured by depositing a thin layer of copper, indium, gallium and
selenide on glass/plastic backing, along with electrodes on the front and back to
collect current.
• thinner film required as:
material has high absorption coefficient
strongly absorbs sunlight 22

23. • layers are thin enough to be flexible, allows them to be deposited on flexible
substrates.
• produces highly flexible, lightweight solar panels.
• Improvements in efficiency have made CIGS an established technology
among alternative cell materials
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25. APPLICATIONS
POWER PLANTS
HOMES
SWIMMIMG
POOLS
POWER
PUMP
SOLAR
CARS
SOLAR
LIGHTING
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