"Assemblies of photovoltaic cells are used to make solar modules which generate electrical power from sunlight. Multiple cells in an integrated group, all oriented in one plane, constitute a solar photovoltaic panel or 'solar photovoltaic module,' as distinguished from a solar thermal module” or “solar hot water panel.” The electrical energy generated from solar modules, colloquially referred to as solar power, is an example of solar energy. A group of connected solar modules is called an “array.”''
"By far, the most prevalent bulk material for solar cells is crystalline silicon (c-Si)"
Wikipedia; Solar Cell
April 4th, 2014 (http://en.wikipedia.org/wiki/Solar_cell)