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What is the energy change known as in photovoltaic cells?

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Last updated date: 20th Jul 2024
Total views: 350.4k
Views today: 4.50k
Answer
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Hint: In order to answer the given question, to know the energy change in a photovoltaic cell, we should go through the concept of photovoltaic cells and we will also explain the working mechanism of photovoltaic cells.

Complete answer:
In photovoltaic cells, the energy changes take place from light energy to electrical energy.
A photovoltaic cell is made up of semiconductor materials that absorb photons from the sun and produce an electric current. Photons are elementary particles that travel at a speed of 300,000 kilometres per second and bear solar radiation. Albert Einstein referred to them as "light seeds" in the 1920s. As photons strike a semiconductor material such as silicon, the electrons in its atoms are released, leaving a vacant area. The stray electrons wander about aimlessly in search of another "void" to fill.
However, in order to generate an electric current, the electrons must all travel in the same direction. Two forms of silicon are used to do this. The sun-exposed silicon layer is doped with phosphorus atoms, which have one more electron than silicon, while the other side is doped with boron atoms, which have one fewer electron. The resulting sandwich functions similarly to a battery: the layer with excess electrons is designated as the negative terminal (n), while the side with a deficit of electrons is designated as the positive terminal (p). At the point where the two layers meet, an electric field is formed.
The electrons are swept to the n-side by an electric field as they are excited by photons, while the holes migrate to the p-side. The electrons and holes are guided to the electrical contacts on both sides before flowing as electrical energy to the external circuit. This produces direct current. An anti-reflective coating is added to the top of the cell to minimize photon loss due to surface reflection.

Note:
Photovoltaic technology makes use of semiconductors to generate electricity through the photoelectric effect. Photons of light (natural or artificial) with sufficient energy will excite electrons to a higher energy state in a photovoltaic cell.