Reflection anisotropy spectroscopy study of the near surface electric field in low-temperature grown GaAs (001)

Abstract
We have evaluated an “effective depletion width” of ⩽45 Å and the sign (n-type/upward band bending) of the near surface electric field in low-temperature grown GaAs (001) using the optical method of reflection anisotropy spectroscopy in the vicinity of the spin-orbit split E1, E1+Δ1 optical features. Our results provide evidence that surface Fermi level pinning occurs for air exposed (001) surfaces of undoped low temperature grown GaAs.