Schottky barrier and interface formation of metal-GaTe(001) interfaces

We studied the deposition of Au, In, Ag, and Al overlayers onto clean-cleaved GaTe(001) surfaces at room temperature by x-ray photoelectron spectroscopy. Gold and In overlayers did not produce evidence of chemical reactions, and neither with cation nor anion outdiffusion. Gold overlayers exhibited no evidence of island formation and a layer-by-layer overlayer coverage. The deposition of In revealed the presence of clustering for a metal thickness higher than 6 Angstrom. On the other hand, the deposition of Al lead to an exchange reaction with a metalliclike Ca phase separation. Core level analysis of the Ag-GaTe interface revealed no noticeable change of the shape of the peaks. The dependence of the peak intensities on overlayer thickness showed an initial layer-by-layer coverage until 1.8 Angstrom, followed by a clustering growth mode. From about 3.7 Angstrom Ag thickness, significant Te outdiffusion was observed. (C) 1998 American Institute of Physics. [S0021-8979(98)09516-4].