What are Solar Cells? All About Solar Power Generation

Did you know that solar power systems can only convert 20% of the sunlight into electricity? It is observed that some good quality commercial solar panels can convert 40% of the sunlight that strikes upon the solar panels.

The main component of a solar panel is incorporated PV cells that convert the sun’s energy into electric power.

Here is a comprehensive overview of solar cells regarding development, performance, and efficiency.

What are Solar Cells?

Solar cells are devices to convert solar energy into electric charge. Typically, solar cells are made of silicon, a semiconductor that generates electricity through photovoltaics. As silicon is the main component of a solar cell, the efficiency of a PV cell depends on the type and quality used in the manufacturing.

What is the Photovoltaic Effect?

The photovoltaic effect is a process which transforms sunlight into electric energy. Solar cells work on the photovoltaic effect. 

It can be explained as; when sunlight strikes the surface of PV cells, electromagnetic radiation is absorbed, and the photon energy is transferred to atoms in the positive and negative points known as the p-n junction. The electrons of the p-n junction get excited and jump to the higher energy state known as the conduction band. 

Also Read: The Benefits of Solar Energy: A Sustainable Solution for a Brighter Future

How Solar Cells Are Made?

Solar cells are composed of semiconductors. A semiconductor represents a material that can conduct electricity better than an insulator but not more efficiently than a conductor; it is called a semi (half) conductor. 

Solar cells are made of two types of semiconductors: type-p (positive) and type-n (negative). The p and n points keep electrons moving and create electric fields when sunlight strikes the PV panels. The p-n junction electrons move in opposite directions, creating an electric field. 

Types of Solar Cells & Their Efficiency

Solar cell types depend upon the material used to manufacture the cell. Most solar cells are made up of silicon and categorized as crystalline, thin film or third-generation solar cells.

Crystalline solar cells: Over 90% of the PV cells comprise crystalline silicon wafers. The crystalline solar cells are further categorized as monocrystalline and polycrystalline solar cells.

Thin-film solar cells: These are made up of amorphous silicon. Thin-film solar cells are 100 times thinner than crystalline solar cells. They are usually made of cadmium-telluride (Cd-Te), copper indium gallium diselenide (CIGS) or organic PV materials.

Third-generation solar cells: These are made up of a combination of crystalline and amorphous solar cells for greater efficiency. Third-generation solar cells are cheaper than the other two categories and more efficient.

The efficiency of a solar cell depends upon the amount of sunlight that strikes on it. The intensity and wavelength of the sunlight determine the total electricity produced by a solar cell. Most PV cells only convert 20% of the energy into electricity. However, under perfect conditions, some good quality solar cells showed 45% energy conversion to produce electricity.

Summary

Solar cells are used to generate renewable energy from sunlight. Each solar panel contains multiple solar cells that capture, absorb, and convert sunlight into electric power. Silicon is the main constituent in manufacturing PV cells that act as semiconductors and allow solar cells to produce electricity. Overall, solar cells have great use in generating renewable energy, yet advancements are being made to make them more reliable, efficient, and low maintenance.

Also Read: The Solar Panel Paradigm - Residential VS Commercial PV Systems