Ab initio-based approach to initial incorporation of Bi on |GaAs(001)-c(4A4)I- surface

The initial incorporation processes of bismuth on GaAs(001)-c(4A4) surface are investigated by using our ab initio-based approach taking chemical potentials in the gas phase into account. The calculated surface phase diagrams obtained by comparing the adsorption energy with the gas-phase chemical potential demonstrate that the form of incorporated Bi depends on the growth conditions. The GaaBi dimer easily adsorbs on the missing dimer region of the c(4A4)I- surface where as the BiaBi dimer adsorption occurs after the GaaAs dimer desorption on the surface with a GaaBi dimer. These results imply that the adsorption of BiaBi dimer accompanied with GaaAs dimer desorption is crucial for the growth process of GaAsBi on GaAs(001) substrates.