IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Wednesday Sessions
       Session SS2-WeA

Paper SS2-WeA3
Electronic State of DNA Molecules on Surface: Cytosine on Cu(110)

Wednesday, October 31, 2001, 2:40 pm, Room 121

Session: Adsorption on Metal Surfaces
Presenter: M. Furukawa, Osaka University, Japan
Authors: M. Furukawa, Osaka University, Japan
T. Komeda, RIKEN, Japan
M. Kawai, RIKEN, Japan
T. Kawai, Osaka University, Japan
H. Ogasawara, RIKEN, Japan
A. Nilsson, Uppsala University, Sweden
Correspondent: Click to Email
Electric property of DNA strands and/or molecules being attractive as they are considered to be a candidate for a piece of molecular system in nano-scale technology. The purpose of the present study is to experimentally define the local electronic state of the molecule of the molecular systems by use of x-ray spectroscopies. Here, X-ray photo-electron spectroscopy (XPS) gives the energy level of core sates against the Fermi level, X-ray absorption spectroscopy (XAS) gives the atom specific energy difference between the core state and the state above the Fermi level. Combining all the information then the atom specific view of the energy levels across the Fermi level be understood. Here we give an example for Cytosine adsorbed on Cu(110) surface, where we have observed the core level for C1s, O1s and N1s and XAS from these core levels to the unoccupied states. As for the orientation of the molecule, electric field direction dependence in the XAS experiment for all C, O and N K edge exhibited that the molecular plane of cytosine sits perpendicular to the surface and also parallel to the [1-10] row of the surface. On of the most interesting feature of the electronic states is the fact that the LUMO state of the molecule is found to sit very close to the Fermi level, indicating that the system has a natural tendency to be electron doped conductor is the level is connected in space.