title: Electron solvation and solvation-induced crystallization of an ammonia film on Ag(111) studied by 2-photon photoemission.
abstract: Intermolecular interaction plays a crucial role in electron solvation in the condensed phase. Here, we present a femtosecond time-resolved and angle-resolved 2-photon photoemission (2PPE) study on the dynamics of electron solvation in a 2-dimensional ammonia film on a metal substrate. While the weakly chemisorbed first monolayer (ML) supports delocalized image-potential (IP) states that resemble those of the bare Ag(111) substrate, an additional monolayer localizes the IP state with a larger binding energy obtained through a pre-solvation process. Structural disorder in the metastable ammonia films (>2 ML) leads to a prominent photoelectron peak that is attributed to the long-lived trapped electron state (e(T)) located at 1.5 eV above the Fermi level. Photoinduced crystallization of the metastable phase, verified by the recovery of a delocalized IP state, is suggested to result from inelastic scattering between interfacial electrons and disordered ammonia molecules.
authors: Department of Chemistry, Seoul National University, Seoul 151-747, Korea.
authors: Hyuksang
authors: H
authors: Kwon
authors: Kiwook
authors: K
authors: Hwang
authors: Juyeon
authors: J
authors: Park
authors: Sunmin
authors: S
authors: Ryu
authors: Seong Keun
authors: SK
authors: Kim
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D003460:Crystallization; D004583:Electrons; D008567:Membranes, Artificial; D056951:Photoelectron Spectroscopy; D011789:Quantum Theory; D012834:Silver / Q000737:chemistry*; D012995:Solubility; D013997:Time Factors
chemical_list: D008567:Membranes, Artificial; D012834:Silver; D000641:Ammonia