Solar Cell

A Solar Cell is a device that converts light energy into electrical energy using the photovoltaic effect. A solar cell is also known as a photovoltaic cell(PV cell). A solar cell is made up of two types of semiconductors, one is called the p-type silicon layer and the n-type silicon layer. So Solar cell is a p-n junction diode.

The solar energy from the sun in the form of photons creates loose electrons on the n-type semiconductor and holes on the p-type semiconductor. These loose electrons are collected on the aluminum layer and start flowing thus resulting in an electric current.

Solar Cell

A solar cell is a device that converts light energy into electrical energy using the photovoltaic effect. It is also known as a Photovoltaic cell.

• A solar cell is made up of two types of silicon semiconductors type, one is n-type silicon semiconductor type and another p-type silicon semiconductor type.
• There is a reflecting coat covered above the solar cell to prevent any external shocks. The solar
• cell’s middle layer is known as the p-n junction diode.
• When the sunlight falls on the solar cel, the solar energy from the sun in the form of photons creates loose electrons on the n-type semiconductor holes on the p-type semiconductor.
• These created loose electrons are collected on the aluminum layer and start flowing, thus resulting in generating the electric current.

Primary Key Terminologies of Solar Cell

• Solar Cel : It is a device which converts sunlight energy into electrical energy using photovoltaic effect.
• Photovoltaic Effect: It is a phenomenon when some materials are exposed to light then it generates electric current.
• Solar Panel : Solar Panel is a collection of solar cells which are connected to produce a higher level electrical output.
• Solar Array: Solar Array is a system where it contains multiple solar panels ,which is designed to generate a large amount of electricity.

Properties of Solar Cell

• Solar Cell is able to convert light energy into electricity.
• Solar Cell higher efficiency and it can convert using Photovoltaic Effect.
• Solar Cell has more durability and resistance to environmental conditions.
• Solar Cells provide long-term performance and has higher life span.
• Solar Cells has no maintenance cost.

Construction of Solar Cell

A solar cell is basically made up of p-n junction diode. Solar cell principle layer is made up of anti-reflective cover glass because it protects semi-conductor materials against the sunlight. Solar Cell consists of small grid patterns with slight metallic strips are available under the glass. The top layer of solar cell is made using glass, metallic strips and anti-reflective coat. Solar cell consists of two semiconductor layers which are made up of p-type and n-type materials. A very thin layer of p-type semiconductor is grown on a relatively thicker n-type semiconductor. We need to apply few finer electrodes on the top of p-type semiconductor layer. So that these electrodes do not obstruct the light to reach the thin p-type layer. Just below the p-type layer there is a p-n junction. We need to provide a current collecting electrode at the bottom of the n-type layer. The base layer of this cell consist of two parts. A rear metallic electrode is beneath the p-type semiconductor and it works with the metallic grid to generate an electric current . A reflective layer is the last layer in this cell used to decrease the loss of light within the system. Solar cell top layer is covered with anti-reflective cover glass to prevent from any mechanical shocks.

Working of Solar Cell

When the light energy falls on a solar panel, then the solar panel absorbs the light energy. Each solar cell in solar panel has an semiconductor which has the properties like insulator and metal. When the energy of sun falls on the panel then a semiconductor material on the panel absorbs, the energy of photons transfers to electrons and allows the flow of electrons through the material like an electric current.

When the sunlight reaches the p-n junction, between the p and n-type semiconductors, photons easily enter through a thin p-type layer. The photons provide energy to the p-n junction, creating electron-hole pairs. This light disrupts the thermal equilibrium condition of the junction, then the free electrons to move to the n-type side of the junction. The holes move to the junction’s p-type side in a similar pattern. As a result, free electrons on the n-type side fail to move past the junction due to a potential barrier. The same barrier potential of the junction blocks the newly created holes, which causes an increased concentration of electrons on one side (at the n-type junction) and holes on the other side. This is the process involved in working of a solar cell.

Different types of Solar Cell

There are mainly classified into three different types of solar cells:

• Monocrystalline solar cells
• Polycrystalline solar cells
• Thin film solar cells

Monocrystalline Solar Cell

• Monocrystalline solar cells are cut from a single ,pure crystal of silicon. Monocrystalline solar cells have cells made of silicon wafers.
• Wafers are assembled into rows and columns to form a rectangle covered with a glass sheet, and framed together.
• Monocrystalline solar cells are easily recognizable because of their black color.
• Appears black because of how light interacts with the pure silicon crystal.
• Have a variety of colors for their back sheets and frames.

Polycrystalline Solar Cell

• Like the monocrystalline solar cells, these polycrystalline solar ones do not require each of the four sides to be cut. Instead, the silicon is melted and poured into square molds . These then form perfectly shaped square cells.
• Monocrystalline solar cells and Polycrystalline solar cells vary in the composition of the silicon itself.
• Polycrystalline solar cells are composed of fragments of silicon crystals that are meted together in a mold before cut into wafers.
• Polycrystalline solar cells have a bluish hue due to the light reflecting off the silicon fragments in the cell in a different way.
• Similar to Monocrystalline solar cells ,Polycrystalline solar cells have a variety of colors for their back sheets and frames.

Thin film Solar Cell

• Thin film solar cells are made from a variety of materials.
• As the name indicates thin film solar cell are often slimmer than other solar cell types.
• The most prevalent type of thin film solar cell is made from Cadmium telluride(CdTe).
• Manufactures place a layer of CdTe between transparent conducting layers that help capture sunlight.
• Copper indium Gallium Selenide(CIGS) panels are popular type of thin-film technology.

Comparison Table for Different Types of Solar Cell

Type	Monocrystalline solar cells	Polycrystalline solar cells	Thin film solar cells
Efficiency	14%-18% solar cell efficiency	12%-14% solar cell efficiency	5%-6% solar cell efficiency
Temperature Tolerance	0% to +5%	-5% to +5%	-3% to +3%
Lifetime	25-30 year lifespan	20-25 year lifespan	15-20 year lifespan
Durability	Hail resistant 25 year P&M	25 year P&M Warranty	25 year P&M Warranty

Applications of Solar Cell

There are many Applications of Solar Cell which we use them in daily life:

• We use solar cells as a power supply to home to reduce the electricity bill.
• We use solar panels for Industrial and commercial businesses to provide power from Solar Arrays.
• We use solar panels for Solar Street Lighting and public spaces streets.
• We use solar panels for agricultural Solar Pumps which is useful for irrigation and powering equipments in farm.
• We use solar panels for off-Grid Power supply systems mainly in remote areas without access to the electricity.
• We use Solar cells can be used for generating electricity for household appliances.
• We use Solar cells can be used in small applications like solar calculators.

Advantages and Disadvantages of Different Types of Solar Cell

Solar Cell Types	Advantages	Disadvantages
Monocrystalline Solar Cells	High Efficiency/performance. Aesthetics Perform better in Low levels of sunlight. Requires Less space.	Higher Cost Lot of waste material when silicon is cut during manufacturing.
Polycrystalline Solar Cells	Low Cost It avoids silicon waste. Easier	Lower Efficiency/performance Requires more space.
Thin film Solar Cells	Portable Flexible Lightweight Aesthetics	Lowest Efficiency/performance Shorter Lifespan.

Conclusion

Solar cell is a device which converts light energy into electrical energy using photovoltaic effect. we have seen the key terminologies and properties of solar cell. we have gone through the working and construction of solar cell. There are three different types of solar cells, we have learned the types of solar cells and applications of solar cells and their uses and we have seen their advantages and disadvantages of solar cell, we have explored the applications using solar cells. Finally we can learn that solar cells play an important role in maintaining the sustainable environment and eco-friendly environment. Solar cells are becoming more popular and efficient and is used in residential home or commercial residence and industrial applications in our daily life.

FAQs on Solar Cell

1. What is the lifespan of Solar Cell?

The lifespan of an Solar Cell generally has 25-30 years, and these come along with warranties based on their performance from the manufacturer.

2. What type of material is used in making solar cells?

Type of material which is used in making solar cells is Crystalline silicon. This Crystalline silicon cells is made by connecting silicon atoms one to one another to form a crystal lattice. This crystal lattice makes efficient conversion of electric current.

3. Why do we need to use Solar Cell?

We need to use Solar Cell because ,Solar cells last for longer time and it has no maintenance cost. Solar Cells provide sustainable environment because no pollution is associated by using solar panels.