TY - JOUR
T1 - Electronic structures of C60 adsorbed on Si(111)-(7 × 7) and Si(001)-(2 × 1) surfaces
AU - Sakamoto, K.
AU - Kondo, D.
AU - Harada, M.
AU - Kimura, A.
AU - Kakizaki, A.
AU - Suto, S.
N1 - Funding Information:
The authors are grateful to Professor A. Kasuya and Professor W. Uchida of Tohoku University for their critical discussions. This work was supported in part by Grant-in-Aid No. 08454072 from the Ministry of Education, Science and Culture, and the Kurata Research Grant.
PY - 1999/8/2
Y1 - 1999/8/2
N2 - We have investigated the electronic structures of C60 molecules adsorbed on the Si(111)-(7 × 7) and Si(001)-(2 × 1) surfaces using photoelectron spectroscopy. The coverage-dependent valence band spectra show that the highest occupied molecular orbital (HOMO) of a C60 molecule splits into two peaks on both surfaces at a coverage of less than 0.25 monolayer. These split peaks are assigned to be the shifted HOMO and the bonding state with the polarization-dependent measurements. The binding energies of the molecular orbitals and the C 1s core level show a small shift on the Si(001)-(2 × 1) surface and no shift on the Si(111)-(7 × 7) surface with decreasing the coverage. These results indicate that the strong interaction between C60 molecules and the surfaces have a covalent character on the Si(111)-(7 × 7) surface, and both covalent and ionic characters on the Si(001)-(2 × 1) surface. We attribute the difference in the charge states of C60 molecules to the different surface structures.
AB - We have investigated the electronic structures of C60 molecules adsorbed on the Si(111)-(7 × 7) and Si(001)-(2 × 1) surfaces using photoelectron spectroscopy. The coverage-dependent valence band spectra show that the highest occupied molecular orbital (HOMO) of a C60 molecule splits into two peaks on both surfaces at a coverage of less than 0.25 monolayer. These split peaks are assigned to be the shifted HOMO and the bonding state with the polarization-dependent measurements. The binding energies of the molecular orbitals and the C 1s core level show a small shift on the Si(001)-(2 × 1) surface and no shift on the Si(111)-(7 × 7) surface with decreasing the coverage. These results indicate that the strong interaction between C60 molecules and the surfaces have a covalent character on the Si(111)-(7 × 7) surface, and both covalent and ionic characters on the Si(001)-(2 × 1) surface. We attribute the difference in the charge states of C60 molecules to the different surface structures.
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U2 - 10.1016/S0039-6028(99)00094-1
DO - 10.1016/S0039-6028(99)00094-1
M3 - Conference article
AN - SCOPUS:0033356591
VL - 433
SP - 642
EP - 646
JO - Surface Science
JF - Surface Science
SN - 0039-6028
T2 - Proceedings of the 1998 14th International Vacuum Congress(ICV-14), 10th Conference on Solid Surfaces(ICSS-10), 5th Conference on Nanometre-scale Science and Technology(NANO-5), 10th International Conference on Quantitative Surface Analysis(QSA-10)
Y2 - 31 August 1998 through 4 September 1998
ER -