The Ultrafast Dynamics of Image Potential State Electrons at the Dimethylsulfoxide/Ag(111) Interface

详细信息    查看全文

• 作者：Matthew L. Strader ; Sean Garrett-Roe ; Paul Szymanski ; Steven T. Shipman ; James E. Johns ; Aram Yang ; Eric Muller ; Charles B. Harris
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：May 1, 2008
• 年：2008
• 卷：112
• 期：17
• 页码：6880 - 6886
• 全文大小：922K
• 年卷期：v.112,no.17(May 1, 2008)
• ISSN：1932-7455

文摘

Angle-resolved two-photon photoemission was used to study the energy relaxation, population decay, andlocalization dynamics of image potential state (IPS) electrons in ultrathin films of dimethylsulfoxide (DMSO)on an Ag(111) substrate. Dynamic energy shifts of 50 ± 10 meV and 220 ± 10 meV were observed for n =1 IPS electrons at one monolayer and two monolayer coverages of DMSO, respectively. The difference inenergy shifts is attributed to rotational hindrance of the molecular dipole in the chemisorptive first monolayer.The finding confirms the proposed mechanism for the low differential capacitance of dimethylsulfoxide atnoble metal interfaces in solution. A novel description of the IPS as a surface capacitance is presented tofacilitate comparisons with electrochemical systems.