ELECTRONIC-PROPERTIES OF CLEAVED(110) AND MBE-GROWN(100) INAS SURFACES, CLEAN AND COVERED WITH AN ULTRA-THIN AG ADLAYER

The initial electronic structure of the pseudomorphic InAs/GaAs(100) h eterostructure as well as that of the Ag/InAs(110) interface at 20 K h ave been studied by synchrotron radiation photoelectron spectroscopy. In the first case we find that the valence band spectra show no eviden ce for the formation of bulk-like energy bands. In the second case we prove for the first time that upon deposition of minute amounts of Ag at low temperature onto cleaved InAs(110) substrates one induces a gia nt movement of the Fermi level well into the conduction band thus crea ting a strong two-dimensional electron channel at the surface.