Britannica Sources used in this answer

Why do solar cells use silicon?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Study how a series of gears in a waterwheel translates a stream's energy to a millstone — energy conversion Before the Industrial Revolution, power came from three main sources: humans, draft animals, and water.
The ingenuity people used in harnessing waterpower can be seen in this medieval-style mill. The waterwheel is turned by a stream and is connected to a shaft that leads into the building. At the other end of the shaft is a gear. The connection of a series of gears translates the power from the stream to a shaft that drives a millstone, which grinds flour from grain.
(30 sec; 1.84MB)

Silicon is the most important semiconductor in the technology sector because its atomic structure allows it to be precisely modified to facilitate the flow of electricity. By "doping" highly purified silicon with elements such as boron or arsenic, engineers can create p-type and n-type materials. When these are joined to form a p–n junction, the material becomes capable of converting sunlight into electric current.12

The effectiveness of silicon in solar cells is rooted in its band gap—the energy required to excite electrons from the valence band to the conduction band. This property allows the material to absorb photons and generate a flow of charge carriers. While single-crystal silicon offers high efficiency, ongoing advancements in materials science—such as the development of thin films, ribbons, and improved manufacturing processes—continue to optimize the balance between production costs and energy conversion efficiency, making silicon the foundational material for photovoltaic technology.2