Electronic properties of clean cleaved {110} GaAs surfaces

Surface photovoltage phenomena: theory, experiment, and applications

“…In order to apply such an approach to SPS data, it is important to consider how well SPV spectra are expected to resemble absorption spectra. Detailed experimental comparisons between SPV and absorption spectra reveal that the two are often similar, but never identical [102,409,410]. Let us consider the sources of this discrepancy: ®rst, the SPV is proportional to the excess carrier density only for a low enough injection of excess carriers, n (see Eq.…”

“…In a series of publications, Gatos's group has both observed sub-bandgap SPV experimentally and analyzed it theoretically. We note that Ostrumova [100], Steinrisser and Hetrick [101], and Dinan et al [102], have also made preliminary attempts at studying sub-bandgap SPV effects at around the same time as Gatos et al, but it was the latter group that did most of the ground-breaking research.…”

Intrinsic and Defect-Induced Surface States of Cleaved GaAs(110)

“…In all cases, the ionization energy is found to be 5.40±0.05 eV confirming previous results. 1 With a value of 1.43 eV for the band gap, this implies that the Fermi level at the surface can be located at its bulk position or at 0.7 eV below the CBM. In the latter case, the surface Fermi level is close to the midgap where people usually say that it is "pinned."…”

Tailing in the Density of States in Amorphous Silicon

“…1 allows one to get an immediate measure of the total uncertainty A2£ expt = 0.15 eV. 6 The metallic distribution also serves to locate the energy of the initial states with respect to the Fermi level. (Since the metal and amorphous silicon are electrically connected, their Fermi levels are equal if thermodynamic equilibrium is not significantly disturbed.)…”

“…valence band is located at or above the extremity of the tail. 6 It has been shown experimentally 4 ' 5 that selection rules based on &-vector conservation do not exist in amorphous semiconductors. Thus, the upper half of the energy distributions of Fig.…”