Did you have an empty feeling inside last week because I forgot about Terminology Tuesday? Fear not! Apologies and here's this week's term: Photovoltaic cells.
Photovoltaic (PV) refers to something capable of producing a voltage when exposed to radiant energy, especially light. A PV cell converts sunlight directly into electricity by the interaction of photons and electrons within the semiconductor material.
To make a PV cell, a material such as silicon is doped with atoms from an element with one more or less electrons than occurs in its matching substrate (the silicon). A thin layer of each material is joined to form a junction. Photons, striking the cell, cause this mismatched electron to be dislodged, creating a current as it moves across the junction.
Through a grid of physical connections, the current is gathered. Various currents and voltages can be supplied through series and parallel arrays of cells.
via the Solar Electric Power Association