C sub 60 bonding and energy-level alignment on metal and semiconductor surfaces

Journal Article · Sun Dec 15 00:00:00 EST 1991 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.44.13747· OSTI ID:5524990

Ohno, T R; Chen, Y; Harvey, S E; Kroll, G H; Weaver, J H ^[1]; Haufler, R E; Smalley, R E ^[2]

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1. Department of Materials Science and Chemical Engineering, University of Minnesota, Minneapolis, Minnesota 55404 (United States)
2. Rice Quantum Institute and Departments of Chemistry and Physics, Rice University, Houston, Texas 77251 (United States)

Electronic-structure studies of C{sub 60} condensed on metal surfaces show that the energy levels derived from the fullerene align with the substrate Fermi level, not the vacuum level. For thick layers grown on metals at 300 K, the binding energy of the C 1{ital s} main line was 284.7 eV and the center of the band derived from the highest occupied molecular orbital was 2.25 eV below the Fermi level. For monolayer amounts of C{sub 60} adsorbed on Au and Cr, however, the C 1{ital s} line was broadened asymmetrically and shifted to lower binding energy, the shakeup features were less distinct, and a band derived from the lowest unoccupied molecular orbital (LUMO) was shifted toward the Fermi level. These monolayer effects demonstrate partial occupancy of a LUMO-derived state, dipole formation, and changes in screening that are associated with LUMO occupancy. Results for C{sub 60} monolayers on {ital n}-type GaAs(110) show transfer of {le}0.02 electron per fullerene, as gauged by substrate band bending. For C{sub 60} on {ital p}-type GaAs, however, the bands remained flat because electron redistribution was not possible, and the C{sub 60}-derived energy levels were aligned to the substrate vacuum level.

• OSTI ID: 5524990
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 44:24; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON
ELECTRONIC STRUCTURE
BISMUTH
BONDING
CHROMIUM
EMISSION SPECTROSCOPY
FERMI LEVEL
GALLIUM ARSENIDES
GOLD
MAGNESIUM
MOLECULAR CRYSTALS
SILVER
ULTRAHIGH VACUUM
ALKALINE EARTH METALS
ARSENIC COMPOUNDS
ARSENIDES
CRYSTALS
ELEMENTS
ENERGY LEVELS
FABRICATION
GALLIUM COMPOUNDS
JOINING
METALS
NONMETALS
PNICTIDES
SPECTROSCOPY
TRANSITION ELEMENTS
360606* - Other Materials- Physical Properties- (1992-)