Effects of Antimony Deposition on Field-Emission Current Density of Ge/Si

TL;DR

This study investigates how antimony deposition affects the field-emission current density of Ge/Si heterostructures, revealing that surface modifications influence emission properties consistent with Fowler-Nordheim theory.

Contribution

It demonstrates the impact of antimony surface coverage on the emission current density of Ge/Si heterostructures, providing insights into surface effects on field emission.

Findings

Antimony coverage increases emission current density.

Ge nanocrystals emit more current than wetting layers.

Surface treatments alter emission characteristics as predicted by Fowler-Nordheim theory.

Abstract

To estimate the field-emission current density of a germanium/silicon heterosystem, 20-nm Ge/Si(100) were grown by molecular beam epitaxy. The surface of one sample was covered with a layer of antimony, which was removed in vacuum prior to the samples being measured. A second sample of Ge/Si was exposed to room air in the absence of antimony. The current-voltage characteristics of both samples obtained by scanning tunneling microscopy were discovered to be in agreement with classical Fowler-Nordheim theory. The density of emission current from Ge nanocrystal exceeds the density of emission current from the wetting layer of Ge/Si. The density of emission current of pure Ge nanocrystal is less than the density of emission current of Ge nanocrystal with adsorption layers.