Theoretical analysis of field emission from metallic nanostructures on Si(100) surfaces

We have analysed effects of submonolayer aluminium adsorption on field emission from Si(100) surfaces using ab initio density functional calculations incorporating scattering states. We have clarified that the electron transfer from aluminium atoms to silicon atoms plays an important role in reducing the local barrier height in front of aluminium atoms, resulting in large emission current. We have also found that, when nanostructures having comparable minimum local barrier height are considered, the relative efficiency of field emission can be explained by the difference in the density of emission sites and the surface local density of states at the Fermi energy