Role of two-hole localization in anion-vacancy formation on the (110) surfaces of InP and GaAs at the third regime of Langmuir evaporation

Abstract

We study the significant Fermi-level effects on the formation rate of anion vacancies on vacuum-cleaved III-V semiconductor surfaces revealed by Semmler et al. ͓J. Chem Phys. 114, 445 ͑2001͔͒, by applying the two-hole localization mechanism of bond rupture on semiconductor surfaces. It is shown that the increasing rate of vacancy formation with hole concentration results from the enhanced rate of two-hole localization at surface anion sites due to reduced energy separations between the Fermi energy and the energy level of the surface state composed of occupied anion dangling bonds.

Excitation-induced structural instability of semiconductor surfaces

“…Based on this result, we evaluated η h (0, t) as a function of time using Z h ≈ 1×10 19 cm −3 . The maximum value of ψ h (=kT η h (0)) for the highest excitation intensity is +0.03 eV, which is considerably less than the calculated valueS of E T (=0.13 eV) and U (=0.83 eV) for InP(110)-(1 × 1) [87]. Therefore, equation ( 16) can be applied for the present analysis.…”

“…Since the quantity J 0 (=C exp(−E d /kT )) in equation ( 16) is the factor to determine the absolute magnitude of the rate, quantitative examination of this constant provides an additional test of the theory. The magnitude of C for P-bond rupture on InP(110)-(1 × 1) can be calculated using equation (11) by inputting parameter values, most of which are obtainable from published data [87]. In the inset of figure 21(a), we plot the calculated value of J 0 as a function of E d .…”

Chemical nature of the anion antisite in dilute phosphide GaAs1−xPx alloy grown at low temperature

“…This change of the electron distribution might weaken the As-Ga bonds at the surface. When the tip scans above the As surface atoms, the subsequent electronic excitation of the weakened bonds might favor the desorption of the atoms through a two-hole localization mechanism, for example [62,63], leaving a vacancy behind. If an As adatom sticks to the tip apex instead of binding with other free As atoms and desorbing as molecules, it could be further released during the next scans to replace a vacancy, giving rise to the switching behavior observed in Fig.…”