Surface States Of GaAs Research Articles

Study of solids and surfaces with polarization-dependent angle-resolved photoemission

Angle-resolved UV photoemission spectroscopy with synchrotron radiation is used to study the quantum structure of bulk and surface states of GaAs (110). The results are used to illustrate methods of utilizing the measured momentum in obtaining and analyzing angle-resolved data. Strong optical-polarization effects observed in the angle-resolved data are analyzed in terms of mirror plane symmetry properties.

Comment on Selection-Rule Effects in Electron-Energy-Loss Spectroscopy of Ge and GaAs Surfaces

Recent energy-loss and photoemission-partial-yield studies of (spin-orbit-split) $d$-core to surface-state transitions imply relative transition probabilities for the ${d}_{\frac{5}{2}}$ and ${d}_{\frac{3}{2}}$ components differing from their orbital degeneracies. This has previously been interpreted as implying $s$ character for the unoccupied surface states of GaAs(110). I present an alternative explanation for this effect assuming only $p$ character for these states and a small exchange interaction.

Photoemission study of surface states of the (110) GaAs surface

A detailed photoemission study of the cleavage face of GaAs shows that there are no empty surface states in the lower half of the energy gap, but empty surface states extend down to about the middle of the energy gap. The empty surface states cause Fermi-level pinning and band bending on $n$-type GaAs, but the bands are approximately flat for $p$-type GaAs. No evidence for filled surface states is found below the valence-band maximum, indicating that any filled surface states below the valence-band maximum have no strong structure and may be strongly mixed with bulk valence-band states. Several theoretical calculations of the surface states for GaAs (110) have been reported which find an empty surface state in good agreement with the results reported here, but the calculations also find a high density of surface states located approximately 0.5 eV below the valence-band maximum, in poor agreement with our results.

Intrinsic (111) surface states of Ge, GaAs, and ZnSe

The intrinsic (111) surface states of Ge, GaAs, and ZnSe are studied using the tight-binding method. The local density of states of atoms on different layers are calculated and the various types of surface states are discussed. The effects of relaxation on the surface states are examined for Ge.

VI-5 GaAs surface and interface states

VI-5 GaAs surface and interface states

Intrinsic localized surface states in GaAs

AbstractSurface states at the cleavage plane of GaAs with energy in the band gap of the bulk band structure and with wave vector corresponding to the point γ at the centre of the [110] surface Brillouin zone are calculated using the empirical pseudopotential method, K · p theory, and the method of matching wavefunctions. The results differ markedly from those previously reported for GaAs in that, when the matching plane is situated midway between two atomic layers, not one but two localized surface states are found. When the matching plane is displaced from the central position, however, one of these localized states disappears from the band gap.