Interface formation on n- and p-CdTe(110) surfaces with Cu and Au

Abstract

The first stages of Cu and Au ultra-high vacuum deposition onto clean, in-situ cleaved (110) surfaces of n- and p-type CdTe single crystals at room temperature have been studied using low energy electron diffraction, Auger electron spectroscopy and photoemission yield spectroscopy. The changes of the measured spectra as a function of metal coverage are well explained for both Cu and Au by the formation of metallic islands which are essentially two-dimensional up to a fraction of a monolayer before becoming more (for Au) or less (for Cu) three-dimensional at higher coverages. The corresponding band bending changes are tentatively evaluated, in spite of the inhomogeneous character of the surface. The presence of a Au induced shallow donor surface state is also recognized below monolayer coverage.