Anomalous pinning of the Fermi level at the InAs(110)-Cu interface obtained at 10 K

Abstract

Detailed investigations of the electronic states of the low temperature (LT) InAs(110)-Cu interface and the EF-pinning for θ ≈ 0.01−0.1 monolayers (ML) give rise to a strongly anomalous EF-pinning (in a position far above the edge of the conduction band, Ec), thus forming a strong two-dimensional electronic channel at the interface (strong downwards band bending). Heating the sample to the room temperature (RT) shifts EF down to a level corresponding to the RT deposition. EF slightly shifts down with respect to Ec at continuous LT-deposition on p-InAs up to θ ≈ 1 ML. The interfaces behave essentially different at RT deposition. Probably pinning of EF takes place on surface states (SS) of two different types. First, SS introduced under adsorption of individual Cu atoms (AIS) and second, under formation of Cu clusters.