Evidence For Surface Reconstruction On Inas Nanocrystals

By means of photoelectron spectroscopy with synchrotron radiation we have studied the surfaces of colloidally prepared InAs nanocrystals in the 30-60 Angstrom size range. We find evidence that specific surface states exist for both In and As atoms and that the passivating trioctylphosphine ligands form chemical bonds with a fraction of the surface In and As atoms. There is evidence for a significant amount of bond-length variation at the nanocrystal surface.