Kakudji, E; Silien, C; Lis, D; Cecchet, F; Nouri, A; Thiry, PA; Peremans, A; Caudano, Y

2010

August

Physica Status Solidi B-Basic Solid State Physics

In situ nonlinear optical spectroscopy of electron-phonon couplings at alkali-doped C(60)/Ag(111) interfaces

Published

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electron-phonon interactions optical spectroscopy properties of surfaces and interfaces SUM-FREQUENCY GENERATION VIBRATIONAL SPECTROSCOPY MOLECULAR THEORY CHARGE-TRANSFER METAL-SURFACES C-60 ADSORPTION 2-COLOR MIRROR MODEL

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1992

1996

We use doubly resonant, infrared-visible sum-frequency generation spectroscopy (DR-SFG) to probe vibrational and electronic properties of C(60) and K-doped C(60) monolayers adsorbed on Ag(111) single crystal under ultra-high vacuum (UHV). We recorded the interface SFG spectra for five visible wavelengths. We observe a strong dependence of the SFG intensity of the totally symmetric Ag(2) mode of the fullerene while scanning the visible wavelength, due to the DR-SFG phenomenon. The SFG intensity of the Ag(2) mode is the strongest at 488?nm and at 532?nm for the pure and fully doped monolayers, respectively. These results demonstrate the occurrence of electronphonon couplings at the C(60)/Ag(111) and saturated K/C(60)/Ag(111) interfaces. They enable us to determine the energy of the coupled electronic transition and to link the electronic resonance to the h(u) (HOMO) to t(1g) (LUMO+1) transition of C(60).

0370-1972

10.1002/pssb.200983947