Electrical interface barriers

Abstract

A review of the phenomena associated with electrical barriers between metals, and insulators and semiconductors is presented. The observed phenomenological rules governing the value of the barrier energies for different metals on the same insulator or semiconductor are presented. The barrier energies on ionic insulators are shown to vary strongly with the metal. While in the case of covalent semiconductors, the barrier energies are relatively independent of the metal. The barrier energy from the metal to the conduction band of the semiconductor is shown to be approximately two-thirds of the semiconductor band gap with certain exceptions. Transport through interfacial barriers is illustrated by discussing the transport through metal–GaSe–metal structures and Mg–SiO_2 structures. Both thermal induced transport over the barrier and tunneling through the barriers are discussed.