Electricity, or the flow of electrons through materials, is exactly what we are trying to generate from solar radiation. As the sun’s radiation makes contact with a solar cell material, the photons of energy create a motion of electrons that can be used to create usable current. The study of solar efficiency depends largely on the mathematics of the motions of these electrons. In following section we will discuss what creates electric current and the physical properties that will later be used to analyze energy capture.
Source: Smith, Linda. “Circle of Lightning”. Nationalgeographic.com. 27 Feb. 2012