Field emission from nanocomposites

Abstract

We study field emission from wide band gap semiconductor-metal nanocomposites. The grains of the wide band gap semiconductor are assumed to be embedded into the layers of metal. Interfacial charge transfer gives rise to metal-induced gap states (MIGS) in the vicinity of the grains. If the density of the semiconductor grains is large, MIGS hybridize with the states in the conduction band of the semiconductor forming a quasi-band. This quasi-band can be populated by the electrons from the metallic matrix through the scattering in the metal-semiconductor composite. The location of the high-lying MIGS in the vicinity of the conduction band of the semiconductor reduces a barrier between these states and the vacuum level. Thus low-threshold field emission from a nanocomposite becomes possible. We support our hypothesis through Monte Carlo simulation of transport through a nanocomposite.