Silicon

Since the discovery of semiconductor properties which are a class of materials which have the unique property that its electrical conductivity can be controlled over a very wide range by the introduction of dopants, the semiconductor has literally changed our world. From a beginning in which the semiconductors were applied only to a very small set of specialized applications has come a technology which is pervasive in today's world. Many have referred to these events as a true revolution, the beginning of the information age. Silicon is one of the most useful semiconductors and a very abundant material, representing about 25 % of the earth's crust. It also provide a controllable, stable, and reproducible surface passivation layer(SiO2) which has made possible semiconductor technology. Because the band gap of silicon is not as large(1.12 eV), electrons in the valency band can be excited to conduction band either thermally or photochemcially which make a good conductance of the silicon. (Plummer 2000)


In situ EC-STM image of Si(111)-H surface.