Solar Cells
SOLAR CELLS A solar cell is an electronic device that produces electricity when light falls on it. The light is absorbed and the cell produces dc voltage and current. The device has a positive and a negative contact between which the voltage is generated and through which the current can flow. Solar cells have no moving parts. Effectively they take light energy and convert it into electrical energy in an electrical circuit in physical process known as the photovoltaic effect. The discovery of the photovoltaic effect is credited to the French physicist, Edmond Becquerel in 1839. He found that by concentrating the sun's light on one side of a battery the output current of the battery could be increased. This revolutionary discovery triggered the idea that one could produce energy from light by an artificial process. In 1883 an American inventor produced a solar cell from a material called selenium, but it was very inefficient. Selenium became used in light-exposure meters for