NEW PHYSICAL FORMULATION OF THE THERMIONIC EMISSION CURRENT AT THE HETEROJUNCTION INTERFACE

The thermionic emission current for electrons across the heterointerface is classically modeled as the difference between two opposing electron fluxes. Here we have developed a new consistent physical model, which includes the carrier degeneracy and nonideal behavior effects, for thermionic emission current at the heterojunction interface. It is shown that the thermionic emission current at the heterojunction interface can be expressed in a simple closed-form formalism which gives the relations among the average directional thermal velocity of electrons, the conduction band discontinuity, and the carrier activities at both sides of the interface. We also discuss the conditions under which the thermionic emission occurs at the heterointerface.