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Structure and Dynamics of Molecular Adlayers on Metal Surfaces: Fundamental electronic processes at metal-molecule interfaces are increasingly important to fields ranging from heterogeneous catalysis to organic electronic devices.

Event Details

Event Dates: 

Wednesday, June 27, 2012 - 4:30am

Speaker Name(s): 

Eric Mueller
Seminar Type/Subject

Event Details & Abstract: 

Time and angle resolved two-photon photoemission spectroscopy (TPPE) is used to investigate the molecular origins of band structure and dynamics observed in a surface bound electron. Three recent projects are discussed. In the first, angle resolved TPPE measures the image state electronic band structure in a monolayer of a molecular semiconductor. The observed energies and intensities measure eigenvalues and eigenvectors of the wave function; confinement is understood through a model of coupled periodic quantum corrals. In a second project, an electron is injected into the electrochemical double layer of a room temperature ionic liquid.Energetics and dynamics of the system reveal charge solvation mechanisms, with implications towards supercapacitors. Finally, a phase change is explored between 2D gas and island phases of adsorbed molecules undergoing random walk motions. Preliminary results compare kinetic Monte Carlo simulations to experimental observations of phase coexistence and slow diffusion dynamics. These three studies use a bound electron to probe surface molecular structure in three dimensions and dynamics on timescales ranging from femtoseconds to hours.