ABSTRACT
A semiconductor material has a resistivity lying between that of a conductor and that of an insulator. In contrast to the granular materials used for resistors, however, a semiconductor establishes its conduction properties through a complex quantum mechanical behavior within a periodic array of semiconductor atoms, that is, within a crystalline structure. Most semiconductor materials are crystals created by atomic bonds through which the valence band of the atoms are filled with eight electrons through sharing of an electron from each of four nearest neighbor atoms. Crystallographic directions and planes are important in both the characteristics and the applications of semiconductor materials since different crystallographic planes can exhibit significantly different physical properties. A semiconductor crystal establishes a periodic arrangement of atoms, leading to a periodic spatial variation of the potential energy throughout the crystal. An intrinsic semiconductor material contains only the elemental atoms of the basic material.
