Occupied and Unoccupied Electronic States on III-V Semiconductor Surfaces

Abstract

Angle-resolved photoemission and inverse photoemission spectroscopy have been applied to investigate the occupied and unoccupied bulk and surface band structure of semiconductors. Together with the in situ combination of both techniques, applicable to a direct determination of surface band gaps, and with angle-resolved constant-initial-state spectroscopy, applicable to the study of empty states above the vacuum level, detailed information on the electronic structure is provided over a wide common energy scale. Here we give a brief review of our recent experimental results on III-V semiconductors, the cleaved (110) surfaces of several compounds and the GaAs (1̄1̄1̄) surface prepared by molecular beam epitaxy. The results will be discussed in view of the available surface models and calculations of the electronic structure.