The Building Blocks: Cells, Modules & Arrays
A photovoltaic cell is a semiconductor device that converts solar radiation into direct current electricity. Since the source of radiation is usually the sun, they are often referred to as solar cells. The individual PV cells are the basic building blocks for modules, which are in turn the building blocks for arrays and complete PV system. Most PV cells use variations of silicon altered by doping to make them suitable semiconductors. Doping is the process of adding small amounts of impurity elements to semiconductors to alter their electrical properties.
The process by which a PV cell converts light into electricity is known as the photovoltaic effect, which is the movement of electrons within a material when it absorbs photons with energy above a certain level. A photon is a unit of electromagnetic radiation which contain various amounts of energy depending on their wavelengths, with higher energies are associated with shorter wavelengths (higher frequency).
PV cells can be produced form a variety of semiconductor materials, the most common is crystalline silicon. It is refined from quartz and silica sands and currently offers the best ratio of performance to cost compared to other competing materials.