Synchrotron radiation photoelectron spectroscopy study of bonding at heterointerfaces between InAs nanocrystals and Se-terminated GaAs

Abstract

Bonding at heterointerfaces between InAs nanocrystals and Se-terminated GaAs is investigated by in situ synchrotron radiation photoelectron spectroscopy (SRPES). The binding energy separation between Ga and GaSe bonding doublet components in the Ga 3 d spectrum for the Se-terminated GaAs surface was estimated for the first time to be 0.3 eV. A distinct spin-orbit component, composed of only the GaAs bulk bonding states, in the As 3 d spectrum for the Se-terminated GaAs surface was also observed. Comparing the core-level SRPES spectra before and after InAs growth, shows that the Se-terminated surface is not disrupted upon InAs epitaxial growth. Furthermore, from the evolution of the peak area ratio of In 4 d to Ga 3 d upon InAs deposition, it is found that, during InAs heteroepitaxial growth on the Se-terminated surface, self-organization of InAs is drastically enhanced compared with the case of As-rich surfaces.