CORE-LEVEL AND VALENCE-BAND STUDIES OF THE (111)2X2 SURFACES OF INSB AND INAS

The valence and core electronic surface states on the (111)2X2 surface s of InSb and InAs have been studied by angle-resolved photoelectron s pectroscopy. Similarities in data show that the vacancy-buckling model , which is known to describe the InSb(111)2x2 surface, also applies to InAs(111)2X2. Three surface valence bands are identified and their di spersions are mapped along symmetry directions in the surface Brilloui n zone. The In 4d core levels show one surface shifted component while no surface shifted components of the Sb 4d or As 3d core levels could be resolved.