Real time observation of surface dielectric responses of GaAs(001) using surface photo-absorption

Surface photo-absorption is used to observe the changes in isotropic and anisotropic surface dielectric responses caused by As desorption during surface conversion from c(4 × 4) to (2 × 4)γ of As-stabilized GaAs(001) surfaces. The anisotropic part agrees with the change in the surface dielectric anisotropy spectrum observed in reflectance-difference measurements during this surface conversion. The spectral evolutions of surface dielectric response are observed in real time with a time resolution of 0.1 s during surface conversion.