This document presents information on dye-sensitized solar cells (DSSCs). It discusses that DSSCs are a type of thin-film solar cell composed of a semiconductor, dye, electrolyte, and counter electrode. DSSCs work by using a dye to absorb sunlight and inject electrons into a semiconductor, like titanium dioxide. The electrons then flow through an external circuit to the counter electrode, while the dye is regenerated by the electrolyte. Though DSSCs have lower efficiency than other thin film cells, they have a better price to performance ratio and do not require pure silicon. The maximum reported conversion efficiency of DSSCs is around 11-15%.

1. S.VASANTH VICTOR
(SENGUNTHAR COLLEGE OF ENGINEERING)
PRESENTED BY,

2. INTRODUCTION
• Dye-sensitized solar cell (DSSC) is the third
generation of solar cell which comprises of
semiconductor electrode, counter electrode and
electrolyte.
• It utilizes the advantage of the wide band gap
semiconductor that sensitized to the light.
• Low cost solar cells
• Invented by Brian o’ Regan and Michael Gratzel
at UC Berkley
• Conversion efficiency lower then other thin
film cells.
• Price/performance ratio is better.
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3. COMPONENTS
The DSSC device consists of 4 components:
Semiconducting electrode
• n-type TiO2 and p-type NiO
Dye-sensitizer
• Light harvesting and electronic transition
Redox mediator
• I- / I3
- or CoII / CoIII complexes
Counter electrode
• Carbon or Pt
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4. DYE SENSITIZED SOLAR CELLS
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5. WORKING PRINCIPLE
• Dye Sensitizers absorb the Sunlight, which
results in electron injection into conduction
band of Oxide (charge separation takes
place at interface of oxide and dye).
• The dye molecules are quite small
(nanometer sized), so in order to capture a
reasonable amount of the incoming light the
layer of dye molecules needs to be made
fairly thick, much thicker than the molecules
themselves.
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6. WORKING PRINCIPLE
• Original state of Dye is subsequently restored by
electron donation from the electrolyte(Redox
iodide/Triodide).
• Iodide is regenerated in turn by the reduction of
triiodide at the counter electrode the circuit being
completed via electron migration through the
external load.
• Redox regeneration at the counter-electrode
(oxidation).
• Dye regeneration reaction (reduction).
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7. WORKING PRINCIPLE
• The voltage generated under illumination
corresponds to the difference between the
Fermi level of the electron in the solid and the
redox potential of the electrolyte.
• Overall the device generates electric power
from light without suffering any permanent
chemical transformation
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8. ENERGY LEVEL DIAGRAM
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9. TiO2
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• TiO2 acts as an absorber of Ultraviolet
(UV) energy, but is virtually
transparent to visible light.
• It is widely available material.
• It is Biocompatible material.
• It is Non toxic.

10. DYE SENSITIZER
• Absorb all light below a threshold wavelength of about 920
nm.
• Contain attachment such as Carboxylate or Phosphonate
group for better attachment with semiconductor oxide.
• Quantum yield of unity for injection of electrons in
Semiconductor oxide.
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11. DYE SENSITIZER
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12. EFFICIENCY
• Electrical power generated =Isc * Voc
• Voc ~ 0.7 (greater then normal Silicon cells)
• Isc for DSSC ~ 20 mA/cm2 an
• Silcon cells ~ 35 mA/cm2
• Peak conversion Efficiency achieved ~ 11 %
• Max . Peak conversion Efficiency ~ 15 %
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13. CONCLUSION
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• DSSCs show the most promising future due to their
independence, environmentally friendly, low maintenance,
and low cost .
• A solar energy system can be installed in any location without
a connection to a power grid.
• The initial investment is expensive. Once the use of electricity
reaches to a certain point, the solar energy is free.
• After installation, there is no recurring cost and it can be used
for a long time.

14. Queries…?
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