Solar cells, also known as photovoltaic cells, are semiconductor devices that convert sunlight into electrical energy through the photovoltaic effect. They are the fundamental building blocks of solar panels and solar arrays used to generate electricity from sunlight. Solar cells typically consist of semiconductor materials such as silicon, which absorb photons from sunlight and generate electron-hole pairs, creating a flow of electric current. Solar cells come in various types, including monocrystalline, polycrystalline, and thin-film solar cells, each offering different efficiencies, costs, and applications. Solar cells find widespread use in residential, commercial, and industrial solar power systems, off-grid applications, portable electronics, and spacecraft, providing renewable and sustainable energy solutions.