SOFT-X-RAY PHOTOEMISSION SPECTROSCOPY OF CHEMICAL-REACTIVITY AT METAL-GASE INTERFACES

The interaction of seven metals with the basal surface of layered solid gallium selenide has been studied by soft X-ray photoemission spectroscopy using synchrotron radiation. The resultant interfaces can be classified as reactive and non-reactive, giving a correlation between interface reactivity and non-Schottky interfacial barrier formation. The suitability of bulk thermodynamic data as a guide to interface reactivity is discussed and it is argued that such schemes should include alloying as a possible reaction path. The spectrum of reactivity observed in the SXPS data is accommodated within a general model of metal-gallium selenide interaction and the use of secondary adlayers to elucidate the nature of metal-semiconductor interfaces is discussed.