Silicon doping in solar cells

Doped Silicon:
This basic flash file I made illustrates how solar cells are made by adding tiny impurities of Gp III and GP V elements to silicon (GP IV element). [Use the keys at the bottom to navigate] The results in an electric field being formed across the p-n junction. Without the built-in electric field the free electrons and free holes created by light photons could not be separated to form a current. A solar cell is a type of large surface area diode.