Electron spectroscopy of GaAs and AlAs surfaces

The low energy electron loss spectra (LELS) and Auger spectra of clean and oxygen contaminated (100) GaAs and AlAs are reported. Losses due to both interband and plasmon excitations are observed. Losses arising from interband transitions from the Ga d-band to empty conduction bands are interpreted in terms of the conduction bands density of states. By changing the primary electron energy both surface and bulk features of the conduction bands can be probed. For clean (100) GaAs a large density of empty surface states is located near the bottom of the conduction band. © 1975.