How does a Solar Cell Work?
Electricity can be produced by solar cells whose principal component consists of a semiconductor that is typically made of silicon. A semiconductor consists of a material that cannot be classified as an isolator or a conductor and whose electrical properties can be influenced by adding foreign substances (doping). The solar cells comprise two adjoining semiconductor layers that are equipped with separate metal contacts and have each been doped, thus creating an n layer (n = negative) with a surplus of electrons and below that, a p layer (p = positive) with an electron deficiency. Due to the difference in concentration, the electrons flow from n into the p area, thus creating an electrical field, or space charge zone, inside the semiconductor structure. The upper n layer in a solar cell is so thin that the photons from sunlight can penetrate it and can only discharge their energy to an electron once they are in the space charge zone. The electron that is activated in this manner follows
Is it possible to create one using simple lab apparatus? Asked by: Megha Answer Solar cells (photovoltaics), use the energy from light photons to create electrical potential between two layers of silicon crystal. The atomic nature of silicon, with some added impurities, is what makes it all possible. The outer orbital electron shell of a silicon atom contains four electrons. Since it takes eight electrons to fill the electron shell, a silicon atom is continually looking for four electrons to bond with. This it finds by bonding covalently with other atoms of silicon forming a characteristic crystalline structure. Silicon atoms thusly joined are very stable and are not electrically conductive, but this is where the impurities come in. By “doping” the silicon with substances such as phosphorus and boron, entirely different electrical properties are introduced into the silicon creating semi-conductive material. For instance, when phosphorus joins with silicon, it creates an N-type semi-con
