What is photovoltaic effect ? Theory of photovoltaic effect

What is photovoltaic effect theory. Photovoltaic effect theory.photovoltaic is the direct conservation of light into electricity at the atomic level. 

Some materials exhibit a property known as the photovoltaic effect that causes property known as the photoelectric effect that causes them to absorb photons of light and release electrons.

Theory of photovoltaic:





When these free electrons are captured, an electric current results that can be used as electricity.

The photovoltaic effect was first noted by a French physicist, Edmund Bequerel, in 1939, who found that certain materials would produce small amounts of electric current when exposed to light. 

In 1905, Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic technology is based, for which he later won a Nobel prize in physics.

The first photovoltaic module was built by bell laboratories in 1954. 

It was billed as a solar battery and was mostly just a curiosity as it was too expensive to gain widespread use. 

In the 1960, the space industry began to make the first serious use of the technology to provide power aboard spacecraft. 

Through the space programs, the technology advanced, it's reliability was established,and the cost began to decline.

 During the energy crisis in the 1970, photovoltaic technology gained recognition as a sources of power for non space application.

Illustrates the operation of a basic photovoltaic cell, also called a solar cell. 

Solar cell are made of the same kinds of semiconductor materials,such as sillicon,used in the microelectronics industry. 

For solar cell , a thin semiconductor wafer is specially treated doped to form an electric field,positive on one side and negative on the other side. 

When light energy strikes the solar cell, electrons are knocked loose from the atom in the semiconductor material. 

If electrical conductors are attached to the positive and negative sides, forming an electrical circuits, the electrons can be captured in the form of an electric current .

 That is electricity. This electricity can then be used to power a load, such a light or a tool. 

A number of solar cells electrically connected to each other and mounted in a support structure or frame is called a photovoltaic module. 

Modules are designed to supply electricity at a certain voltage, such as a common 12 volts system. 

The current produced is directly dependent on how much light strikes the module.

 Multiple modules can be wired together to form an array. 

In general,the larger the area of a module or array,the more electricity that will be produced. 

Photovoltaic modules and arrays produce direct current electricity. 

They can be connected in both series and parallel electrical arrangments to produces any required voltage and current combination.

Optical loss in photovoltaic cell:


Mismatch of the band gap of the material with the solar spectrum. 

Total spectrum of solar energy is not absorbed.

Reflection loss of light.

Less intensity of light.

Remedy:

Selection of suitable material increases the efficiency of solar cell.

Instead of using single material to design the solar cell, use different material to design the random type solar cell for utillizing total spectrum.

Use anti reflection coating to reduce the reflection loss.

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