Geethanjali College of Engineering &
Technology.
SOLID STATE PHYSICS PROJECT
TOPIC: SOLAR CELL.
K. Murali Karthik(24R11A0465)
T. Hemanth Rao(24R11A0482)
Agastya Kumar(24R11A0444)
WHAT IS A SOLAR CELL:
• A solar cell, also known as a photovoltaic (PV) cell, is
an electronic device that
• converts the energy of light directly into electricity by means of
the photovoltaic effect.
• It is a form of photoelectric cell, defined as a device whose
electrical
• characteristics (such as current, voltage, or resistance) vary
when exposed to light.
• Solar cells are the building blocks of photovoltaic modules,
otherwise known as solar panels.
CONSTRUCTION:
• A solar cell, or photovoltaic cell, is primarily
composed of two layers of silicon: a p-type and an
n-type layer. These layers create a p-n junction,
which is crucial for the cell's operation.
• The Basic Structure:
• P-type Silicon Layer:
• Doped with impurities like boron
• Has a deficiency of electrons, resulting in "holes"
(positive charge carriers).
• N-type Silicon Layer:
• -Doped with impurities like phosphorus
• -Has an excess of electrons (negative charge
carriers).
• P-N Junction:
• The interface between the p-type and n-type layers
• Creates an electric field due to the diffusion of charge carriers
• Additional Layers and Coatings:
• Anti-Reflective Coating:
• Reduces light reflection, maximizing light absorption
• Metal Contacts:
• Collect and transport the generated electric current
• Typically made of aluminum or silver
• Encapsulation:
• -Protects the cell from environmental factors like moisture and dust
• -Often made of glass or polymer.
• MATERIALS USED:
• 1.Sillicon
• 2.Cadmium telinide
• 3.GaAs
• 4.CuInSe2
WORKING:
• Solar Cell works on the principal of
Photovoltaic mode(No bias mode)
• Photon Absorption:
• When sunlight strikes a solar cell,
photons (particles of light) are absorbed
by the semiconductor material, typically
silicon.
• Electron Excitation:
• The absorbed energy excites electrons
in the silicon atoms, allowing them to
break free from their bonds.
• Charge Separation:
• The p-n junction, a boundary between a p-type and an n-type semiconductor,
plays a crucial role in separating the excited electrons.
• The p-type layer has a deficiency of electrons (holes), while the n-type layer has an excess of
electrons.
• Electric Current:
• The separated electrons and holes create an electric potential difference across the p-n
junction.
• If an external circuit is connected to the cell, the electrons flow through the circuit, generating
an electric current.
• Fill Factor in Solar Cells:
• The Fill Factor (FF) is a crucial parameter that measures the quality and efficiency of a solar
cell.
• It essentially quantifies how well a solar cell converts the maximum possible power output
into actual power.
• Fill factor(FF) = (Vm*Im)/(Voc*Isc).
V-I CHARACTERICTS:
• Short-Circuit Current (Isc):
• The current flowing through
the cell when the terminals are
short-circuited.
• This occurs at zero voltage.
• Open-Circuit Voltage (Voc):
• The voltage across the cell terminals when
no current is flowing.
• This occurs at zero current.
• Maximum Power Point (MPP):
• The point on the curve where the product of voltage and current is maximum.
• This is the ideal operating point for a solar cell.
• Factors Affecting V-I Characteristics:
• Solar Irradiance: Higher irradiance leads to higher short-circuit current and
open-circuit voltage.
• Temperature: Temperature affects the bandgap of the semiconductor material,
influencing the V-I curve.
• Cell Quality: Defects and impurities in the cell material can degrade its
performance.
APPLICATIONS:
• Residential and Commercial Power
Generation
• Remote Power Systems.
• Solar-Powered Gadgets.
• Solar Water Heating.
• Solar-Powered Vehicles.
ADVANTAGES:
• Clean and Renewable Energy.
• Lower Electricity Bills.
• Low Maintenance.
• Versatility.
DISADVANTAGES:
• High Initial Cost
• Weather Dependence
• Technological Limitations:
• Although solar cell technology has advanced significantly,
there are still limitations in terms of efficiency and cost.
