Solar energy is used by solar cells, which is a clean, renewable source of energy. In-depth discussion of the definition, kinds, mechanism, Perovskite Solar Cell Revolution, uses, benefits, and drawbacks of solar cells will be provided in this essay.
What is Solar Cell
Light (optical) energy is converted to current by the solar cell. Essentially, it functions as a photovoltaic cell that generates electricity when exposed to light. Solar cells efficiently collect sunlight and transform into batteries when they are subjected to light energy. Solar modules and panels are collections of solar cells, and solar arrays are collections of solar arrays. Numerous devices, including calculators and home rooftop solar panels, employ them.
Positive layer (p-type) and negative layer are the two layers that make up a photovoltaic cell or solar cell (n-type). Historically, silicon single crystal was used to make cells, and this material is still a favourite today. As a result of silicon’s weak electrical conductivity, doping silicon is required. Silicon is doped with either phosphorus or boron to produce n-type or p-type areas, depending. Thus, the p-n junction generates an electric field and functions as a diode, aiding in the transfer of electrons from the p-region to the n-region.
How Do Solar Cells Function
Consider a solar cell composed of silicon with a positive layer (p-type) and a negative layer to comprehend the operating principle (n-type). Silicon is doped with boron, which has one fewer electron in its valence shell than silicon, and is used to form the p-type region. As a result, a “hole” or electron valency is produced. Similar to how silicon is doped, phosphorus, which has one more electron in its valence shell than silicon, is used to generate the n-type area. One electron is free to migrate when covalent bonding takes place.
N- and p-type silicon layers are sandwiched together to form solar cells. At the intersection of two layers, where the Solar Cell is exposed to sunlight, electrons and holes are near to one another. According to Coulomb’s law, a force exists between electrons and holes that cause them to travel from the n-region to the p-region and occupy holes. This causes positive ions on the n-side and negative ions on the p-side.
A depletion layer is created as a result, stopping further electron transport. The existence of ions with opposing charges causes the creation of an electric field. Electrons go from the n-region to the p-region crossing the depletion layer and then pass through the metallic wire to the n-region when the n-type and p-type layers are externally connected to a metallic wire. Electricity flows as a result of this.
Various Solar Cell Types
They are divided into three categories. As follows:
- First Generation Cells
- Second Generation Cells
- Third Generation Cells
Cells of the First Generation
Single crystal and multicrystalline silicon cells make up this generation of solar cells. These were first introduced by Bell Labs and are the oldest. The effectiveness of these cells is well documented. Each of these cells, which are made on silicon wafers, has a power output of 2–3 Watts. To enhance power, solar cells are assembled into solar modules or panels. Producing these cells is expensive.
Cells of a Later Generation
Thin-film solar cells made of amorphous silicon, cadmium telluride/cadmium sulphide, and copper indium gallium selenide (CIGS) are the most well-known products of the second generation of cells. Although they are more expensive to create than first-generation cells, their efficiency is lower. These cells are constructed from a series of 1-4 m thick layers that are deposited on a variety of substrates, including glass, polymer, and metal. They are adaptable and visually appealing. Calculators utilize amorphous silicon cells.
Cells of the Third Generation
Third Generation Cells includes the newest and most promising technology. The primary goal of the research is to create the highest efficient Solar Cells that are also readily producible. Also targeted are cells that are free of toxins. Nanocrystal-based solar cells, polymer-based solar cells, dye-sensitized cells, and organic-inorganic halide cells are examples of third generation cells.
The uses of solar cells
Among the applications are:
- In portable power supply, they are employed.
- They are frequently utilized for heating, water pumping, etc.
- They are employed in satellites with solar power.
- Both watches and calculators use them.
- They are employed in systems for public illumination.
Benefits of Solar Cells
The benefits comprise:
- It is a renewable and sustainable source of power.
- Low maintenance.
- High durability.
- The raw materials needed to make third-generation cells are reasonably priced.
The drawbacks of solar cells
The drawbacks are:
- Solar panel installation is pricey at first.
- Dependence on weather has an impact on its effectiveness.
- Electric shorts and house fires may result from damaged solar panel systems.
- Takes up a lot of room.
- They are more prone to injury.
- Cadmium-based second-generation cells are extremely hazardous.
- The cost of the raw materials needed to make second-generation cells is high.
Conclusion
Solar cell research and development is continuing to harness the sun’s plentiful energy, lowering the need for fossil fuels.
