To separate electrical charges, crystalline silicon cells must have a built-in electric field. Light shining on crystalline silicon may free electrons within the crystal lattice, but for these electrons to do useful work—such as provide electricity to a light bulb—they must be separated and directed into an electrical circuit.
Crystalline silicon cells are made of silicon atoms connected to one another to form a crystal lattice. This lattice comprises the solid material that forms the photovoltaic (PV) cell's semiconductors. This section describes the atomic structure and bandgap energy of these cells.
Solar energy technologies produce electricity from the energy of the sun. Small solar energy systems can provide electricity for homes, businesses, and remote power needs. Larger solar energy systems provide more electricity for contribution to the electric power system.