What is a Solar Cell and How Does it Work?

Solar cells are becoming more commonplace as the adoption of renewable energy technologies increases and the need to cut carbon emissions becomes more apparent.

Although solar cells have been around for some time, many people may not understand the purpose of these objects or the principles of how they operate. To clear that up, here is a quick exploration of all things solar cell-related.

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Silicon in solar cells interacts with photons

What is a solar cell?

In simple terms, a solar cell is a device which absorbs the energy emitted by the sun and turns it into electricity which can either be stored for later use or harness immediately.

You will find solar cells in many places, whether integrated directly into portable devices such as calculators to provide power on the move, or installed on buildings and structures to generate electricity that can be used for almost any purpose.

Solar cells are even being deployed to power entire data centres, generating hundreds of megawatts of power to dramatically reduce the carbon footprint of the technologies which keep many digital services up and running today.

How does a solar cell work?

Solar cells are typically manufactured with silicon acting as the semiconductor to convert sunlight into electricity. This silicon is drilled or cut into thin wafers and also marked using fiber lasers to identify specific components with ease.

The silicon substrates within the film are exposed to light, with the individual particles of light (known as photons) bumping into the atoms of the silicon and in doing so passing on the energy they possess. This is a little like the way the balls of a Newton’s cradle knock into one another and transfer their momentum to their counterparts, only in the case of a solar cell the electrons which are hit by the photons are freed from their original atoms altogether.

The atoms of silicon within solar cells are organised in a way that means there is an innate electrical imbalance, causing the loose electrons to jump from one type of the material to its counterpart. An electric field is generated and the imbalance is maintained thanks to the fact that silicon is a semiconductor, as mentioned earlier.

The chain of events created by the impact of the photos from the sun allows for power to be produced, which can then be used for whatever application is required.

What types of silicon are used?

It is worth exploring the differences between the two varieties of silicon created to manufacture solar cells. These film substrates are not made from pure silicon, but rather from a material that is predominantly silicon but with a handful of other elements integrated into the structure to create the necessary electromagnetic imbalance covered above.

These two varieties are known as n-type silicon and p-type silicon, with the former possessing spare electrons while the latter has fewer electrons than usual. As atoms are generally striving to achieve a balance, it is easy for the impact of photons to coax electrons from n-type silicon to make the leap over to p-type silicon.

In the case of n-type silicon, it is the doping with phosphorous gas which gives it its negative charge, while p-type silicon is instead adapted using boron gas.

It is not just solar cells which take advantage of these silicon varieties, but also other transistors and electronic components used across a wide range of devices and systems.

Solar cells provide clean power from sunlight

Solar cells provide clean power from sunlight

Where are they found?

Although we have touched on the types of places where solar cells are widely used, it is worth investigating this a little more thoroughly to better appreciate how effective they can be in the right circumstances.

The first pocket calculators to come with built-in solar cells emerged in the 1970s and this is likely the first place that most people encounter the technology in everyday use. The low power requirements of such devices mean that the most basic solar cells are well suited to provide the required electricity.

Solar cells are also immensely useful in providing power to the satellites that orbit the planet in their hundreds, as well as to the International Space Station and the deep space exploration craft that have been launched over the years. Outside of the Earth’s atmosphere, access to sunlight is guaranteed and so solar cells can be particularly potent in this context.

For terrestrial use, solar cells are limited by the availability of sunlight, meaning that they cannot operate during the hours of darkness. They are also less effective in parts of the world where strong sunlight is less consistently available.

Even so, they are still becoming more accepted for domestic and commercial applications alike, reducing emissions and cutting costs compared to traditional power generation techniques that rely on fossil fuels.

Contacting SPI Lasers for enquiries

We hope you have enjoyed this article and welcome all enquiries relating to the purchase of any of our fiber laser range. Buy our fiber lasers for incorporation into your machine(s) to assist in manufacturing solar cells and for use in many applications such as cutting, drilling, engraving and welding.

Contact our team today, our contact details are here, we look forward to hearing from you.


Image Sources: Ulleo and Hans


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