Nonlinear optical studies of molecular interaction with a silver surface

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:141462

Ying, Z C; Li, C M; Dai, H L ^[1]

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1. Univ. of Pennyslvania, Philadelphia, PA (United States)

Optical techniques, especially nonlinear optical techniques, can be used to study surfaces and interfaces in a variety of environment with ultrahigh time resolution. In this laboratory, the authors have used second-harmonic generation (SHG) to probe electronic structures of clean surfaces and surfaces with atomic and molecular adsorbates. In a study of pyridine molecules adsorbed on Ag(111), for example, it is found that charge transfer due to the adsorption of pyridine at monolayer coverages leads to an increase of the isotopic component of the SHG signal by two orders of magnitude. At the multilayer regime, the anisotropic component exhibits an oscillating pattern due to multiple reflections of the laser beams. It was found that the frequency and angular dependences of SHG can be adequately explained by the effects of adsorption on linear susceptibility of the interface. In addition to SHG, a new surface science technique based on four-wave mixing is being developed. The experiment is conducted initially for a monolayer of dye molecules adsorbed on a fused-silica surface in air and will be extended to semiconductor and metal surfaces in ultrahigh vacuum.

• OSTI ID: 141462
• Report Number(s): CONF-930304--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ADSORPTION
CHEMICAL REACTIONS
ELECTRON TRANSFER
FREQUENCY MIXING
HARMONIC GENERATION
NONLINEAR OPTICS
PYRIDINE
SILVER
SURFACE PROPERTIES