Microscopic electronic structure and growth mode of Sn/InSb(111) interfaces

Abstract

The electronic properties and growth mode of Sn/InSb(111) interfaces have been investigated by angular resolved photoemission spectroscopy (ARUPS), high energy electron diffraction (RHEED), and work function measurements. For Sn coverages of ∼1 ML the Fermi level is pinned at the bottom of the conduction band. The interfacial growth is heteroepitaxial and extends to a thickness of ∼5 ML of Sn. This is followed by the formation of diamond structured α-Sn up to ∼40 ML. Beyond this thickness three dimensional island growth starts and the films are a mixture of semiconducting α-Sn and metallic β-Sn. Above ∼120 ML Sn, the surface region consists of pure β-Sn while due to a strong substrate stabilization effect the interface region still consists of the α-Sn phase.