Ab initio-based approach to initial growth processes on $\text{GaAs}(111)B\text{\ensuremath{-}}(2\ifmmode\times\else\texttimes\fi{}2)$ surfaces: Self-surfactant effect of Ga adatoms revisited

Ab initio-based approach to initial growth processes on $GaAs (111) B − (2 \times 2)$ surfaces: Self-surfactant effect of Ga adatoms revisited

Hiroaki Tatematsu, Kosuke Sano, Toru Akiyama, Kohji Nakamura, and Tomonori Ito

Phys. Rev. B 77, 233306 – Published 16 June 2008

Abstract

The initial growth processes on $GaAs (111) B − (2 \times 2)$ surfaces are investigated using our ab initio-based approach, in which desorption behavior of As atoms is described by comparing the calculated desorption energy obtained by total-energy electronic-structure calculations with the chemical potential estimated by quantum statistical mechanics. We find that the As-trimer desorption on the $(2 \times 2)$ surfaces with Ga adatoms occurs beyond 400–700 K while the desorption without Ga adatom does beyond 800–1000 K. The promotion of the As-trimer desorption triggered by Ga adatoms called “self-surfactant effect” is also found to be interpreted in terms of the band-energy stabilization.