2. Outline:
• Physics Of PV Conversion
• The three generations of solar cells
– First Generation
– Second Generation
– Third Generation
• Solar Cell Materials
• Emerging Photovoltaic
• Timeline of Solar Photovoltaic cell
• Conclusion
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5. First-generation - based on expensive silicon wafers; 85% of the
current commercial market.
Second-generation - based on thin films of materials such as
amorphous silicon, Nano crystalline silicon, cadmium telluride,
or copper indium selenide. The materials are less expensive, but
research is needed to raise the cells' efficiency.
Third-generation - the research goal: a dramatic increase in
efficiency that maintains the cost advantage of second-
generation materials. Their design may make use of carrier
multiplication, hot electron extraction, multiple junctions,
sunlight concentration, or new materials.
The three generations of solar cells
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6. Continued…
6
Goal: Achieving high
efficiency from
inexpensive materials with
so-called third-generation
cells
The horizontal axis
represents the cost of the
solar module only; it must
be approximately doubled
to include the costs of
packaging and mounting.
Dotted lines indicate the
cost per watt of peak
power.
7. Solar PV Materials:
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Efficiency Of Cells (Lab)
Amorphous silicon (multijunction) 13.2%
Cadmium Telluride (CdTe) thin film 16.5%
Copper-Indium-Gallium-Selenium (CIGS) 19.9%
Gallium Arsenide (GaAs) Cell 20%
Multi crystalline or polycrystalline silicon 20.3%
Mono crystalline silicon 23.4%
High performance mono-crystalline silicon 24.7%
Triple-junction (GaInP/GaAs/Ge) cell 40.7%
8. Emerging Photovoltaic:
• Organic Photovoltaic
An organic photovoltaic cell (OPVC) is a
photovoltaic cell that uses organic electronics--a
branch of electronics that deals with conductive
organic polymers or small organic molecules for
light absorption and charge transport.
An organic photovoltaic cell, comprising
an organic photoconductive layer comprising a
charge generating substance and a charge
transporting substance, and a protective layer
covering the organic photoconductive layer and
blocking low-wavelength light of below 450 nm.
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9. Continued…
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The optical absorption coefficient of organic
molecules is high, so a large amount of light can
be absorbed with a small amount of materials.
The power plastic(OPVC) itself has low production
costs in high volumes.
The main disadvantages associated with organic
photovoltaic cells are low efficiency, low stability
and low strength compared to inorganic
photovoltaic cells.
10. • Dye-sensitized solar cell
It is based on a semiconductor formed
between a photo-sensitized anode and an electrolyte.
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The DSSC has a number of attractive features:
• semi-flexible and semi-transparent
• most of the materials used are low-cost
Disadvantages:
• Low Efficiency(7-8%)
11. • Transparent conducting film
Transparent conductive oxides (TCO) are doped metal
oxides used in optoelectronic devices such as flat
panel displays and Photovoltaic (including inorganic
devices, organic devices). Most of these films are
fabricated
with polycrystalline or amorphous microstructures.
• Quantum dot solar cell
A quantum dot solar cell is a solar cell design that
uses quantum dot as the absorbing photovoltaic
material. It attempts to replace bulk materials such
as silicon, copper indium gallium selenide (CIGS)
or CdTe.
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13. Conclusion
Many of us believe that photovoltaics could become the major
energy source for the world in the later part of this century, but
continued research and development are required in several areas:
PV system costs must be reduced significantly
Improved conversion efficiencies
Long-term reliability must be ensured for new PV materials &
devices
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