Energy Distribution in Field Emission from Adsorbate Covered Surfaces

Abstract

A calculation of the total-energy distribution of field-emitted electrons in the presence of chemisorbed atoms shows that $\frac{[j(\ensuremath{\omega})\ensuremath{-}{j}_{0}(\ensuremath{\omega})]}{{j}_{0}(\ensuremath{\omega})}=\mathrm{Im}{G}_{\mathrm{aa}}(\ensuremath{\omega})\mathrm{exp}[{(\frac{\ensuremath{-}2m\ensuremath{\omega}}{{\ensuremath{\hbar}}^{2}})}^{\frac{1}{2}}{x}_{a}]$, where $j(\ensuremath{\omega})$ and ${j}_{0}(\ensuremath{\omega})$ are the current densities in energy in the presence and absence of absorbate, respectively; $\ensuremath{\omega}$ is measured from the vacuum level; ${x}_{a}$ is the surface-absorbate distance; and ${\ensuremath{\pi}}^{\ensuremath{-}1}\mathrm{Im}{G}_{\mathrm{aa}}$ is the local density of states at the absorbate. This result is general and independent of the explicit form of ${G}_{\mathrm{aa}}$.