Structural, electronic, and dynamical properties of Si(110) capped with a monolayer of GaAs

Abstract

Using a first-principles pseudopotential technique, we have presented structural and electronic properties of the Si(110) surface capped with a monolayer of GaAs. These results are further used to investigate the phonon-dispersion curves and the phonon density of states of the system. Both an adiabatic bond-charge model and a linear-response scheme to the ab initio pseudopotential method have been employed for the study of the phonon properties, and the results obtained from the two methods are compared systematically. The surface acoustic-phonon modes of this system have energies similar to those on the clean GaAs(110) surface, while the highest surface optical-phonon mode of this system lies at a higher energy than the corresponding mode for the clean GaAs(110) surface. These and other similarities and dissimilarities between the GaAs:Si(110) and GaAs(110) surfaces are discussed and explained.