Photoemission spectroscopy of germanium nanocrystal films

Photoemission spectroscopy measurements have been performed on films of individual germanium nanocrystals. The Ge 3d core-level photoemission reveals mainly bulk-like coordinated atoms and structural disorder on the nanocrystal surface. The Ge 3d plasmon excitation exhibits a reduced bulk- and an increased surface-plasmon contribution underlining the importance of the surface region to the overall particle electronic structure. In the Ge nanocrystal valence-band photoemission features similar to amorphous-Ge are found, further indicating structural disorder in the surface region of the nanocrystals. (C) 2002 Elsevier Science B.V. All rights reserved.