Modified Thomas-Fermi theory for depletion and accumulation layers inn-type GaAs

A modified Thomas-Fermi approximation (TFA) developed originally for inversion layers is used to calculate electron-density profiles, the spatial dependences of the potential, surface potentials, and the energies of bound states of depletion and accumulation layers in n-type GaAs. Remarkable agreement with recently published results of self-consistent calculations of Ehlers and Mills [Phys. Rev. B 34, 3939 (1986)] is achieved. All deficiencies of the conventional TFA discussed there are removed. Methodological advantages of the modified TFA are discussed.