What is Solar cell?
'''Solar cells''' are [[semiconductor]] devices that convert [[light]] to [[electricity]]. They have many applications. They have long been used in situations where electrical power from the [[Electric power transmission|grid]] is unavailable, such as in remote area power systems, [[Earth]]-orbiting [[satellites]] and space probes, consumer systems, e.g. handheld [[calculator]]s or wrist watches, remote [[radiotelephone]]s and [[water]] pumping applications. More recently, they are starting to be used in assemblies of solar modules connected to the [[Electric power transmission|electricity grid]] through an [[inverter]], often in combination with [[net metering]]. Solar cells are regarded as one of the key technologies of [[solar energy]] towards a [[sustainable energy]] supply. ==Three generations of development== ===First=== The '''first generation photovoltaic''' consists of a large-area, single layer [[p-n junction]] [[diode]], which is capable of generating usable electrical [[energy]] from light sources with the [[wavelength]]s of sunlight. These cells are typically made using a [[silicon]] wafer. First generation photovoltaic cells (also known as silicon wafer-based solar cells) are the dominant technology in the commercial production of solar cells, accounting for more than 86% of the solar cell market. ===Second=== The '''second generation''' of photovoltaic materials is based on the use of thin-film deposits of semiconductors. These devices were initially designed to be high-efficiency, multiple junction photovoltaic cells. Later, the advantage of using a thin-film of material was noted, reducing the mass of material required for cell design. This contributed to a prediction of greatly reduced costs for thin film solar cells. Currently (2007) there are different technologies/semiconductor materials under investigation or in mass production, such as amorphous silicon, poly-crystalline silicon, micro-crystalline silicon, cadmium telluride, copper indium selenide/sulfide. Typically, the efficiencies of