Temperature dependence of the Ge(111) surface electronic structure probed by inelastic H atom scattering

Experimental methods capable of determining the electronic properties of the surfaces of materials suffer from severe limitations, including interference from bulk electronic states, insensitivity to unoccupied states, and the requirement that the material be conducting. In this work, we introduce inelastic H atom scattering as a tool to probe the electronic structures of surfaces, which can be applied to both conducting and nonconducting samples while exhibiting exceptional surface sensitivity. We illustrate the method for the example of Ge(111). The measurements show a semiconducting surface at low temperature that continuously becomes increasingly metallic at high temperature.