Influence of the substrate lattice structure on the formation of quantum well states in thinIn and Pb films on silicon

Abstract

The substrate lattice structure may have a considerable influence on the formation ofquantum well states in a metal overlayer material. Here we study three modelsystems using angle resolved photoemission and low energy electron diffraction:indium films on Si(111) and indium and lead on Si(100). Data are comparedwith theoretical predictions based on density functional theory. We find thatthe interaction between the substrate and the overlayer strongly influences theformation of quantum well states; indium layers only exhibit well defined quantumwell states when the layer relaxes from an initial face-centred cubic to the bulkbody-centred tetragonal lattice structure. For Pb layers on Si(100) a change in growthorientation inhibits the formation of quantum well states in films thicker than 2 ML.