Field Emission from Semiconductors

The field emission current from a simple semiconductor has been evaluated in a manner similar to that employed by Fowler and Nordheim for a metal. It is shown that special effects will be associated with the state of the semiconductor surface. The presence of an appreciable number of surface states should give very low currents until fields high enough to break down the internal barrier are applied. When this occurs, or if there are no surface states at all, the field will penetrate into the semiconductor and lead to a lowering of the conduction band edge. This causes degeneracy in the electron distribution near the surface region and a greatly enhanced emission not unlike that of a metal