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 + Delta1 optical features. Our results provide evidence that surface Fermi level pinning occurs for air exposed (001) surfaces of undoped low temperature grown GaAs.
Date of this Version
Applied Physics Letters: Volume 70, Issue 9 doi: 10.1063/1.118499