A photoelectric cell designed to convert sunlight into electrical energy, typically consisting of layers or sheets of specially prepared silicon. Electrons, displaced through the photoelectric effect by the Sun's radiant energy in one layer, flow across a junction to the other layer, creating a voltage across the layers that can provide power to an external circuit. Solar cells are used as power supplies in calculators, satellites, and other devices, and as a primary source of electricity in remote locations.
When light penetrates a solar cell and reaches the lower charged layer, its energy causes atoms there to release electrons, which drift to the upper layer, giving the upper layer a net negative charge and the lower layer a net positive charge. This voltage difference can be used as a source of electrical energy.