AVS 56th International Symposium & Exhibition
    Applied Surface Science Tuesday Sessions
       Session AS-TuP

Paper AS-TuP16
Surface Potential Measurement of Organo-Chalcogenide Self-Assembled Monolayers using Kelvin Probe Force Microscopy

Tuesday, November 10, 2009, 6:00 pm, Room Hall 3

Session: Applied Surface Science Poster Session
Presenter: T. Ichii, Kyoto University, Japan
Authors: T. Ichii, Kyoto University, Japan
S. Nanjo, Kyoto University, Japan
S. Ikebukuro, Kyoto University, Japan
K, Miki, Kyoto University, Japan
K. Murase, Kyoto University, Japan
K. Ohe, Kyoto University, Japan
H. Sugimura, Kyoto University, Japan
Correspondent: Click to Email
Organo-chalcogenides (sulfide, selenide, and telluride) have been expected to play an important roll in molecular electronics because they can be bound onto noble metals. Functional groups with the chalcogene atoms in these molecules act as anchoring groups, and the molecule-metal bindings can be modified by changing the atom species. Some of the organo-chalcogenides are formed into self-assembled monolayers (SAMs) and they have been intensively studied as model structures of molecule-metal binding.

Kelvin probe force microscopy (KFM), which is one of scanning probe techniques, is an outstanding method for the investigation of local surface potential on the nanometer scale. Since surface potential of organic monolayers on substrates reflects dipole moment of the organic molecules and interfacial dipole moment between the molecules and the substrate, KFM allows us to clarify how the anchoring groups effect on electric properties of the molecule-metal bindings.

In this study, we investigated surface potential distribution of phase-separated SAMs composed of organosulfide and organoselenide using KFM. Dibenzyl-disulfied (BS), dibenzyl-diselenide (BSe) and 3-mercapto-N-octylpropioneamide (1ATC8) were used and phase-separated SAMs of BS/1ATC8 and those of BSe/1ATC8 were prepared. The 1ATC8 areas in the SAMs were used as a reference in the surface potential measurement. The surface potential of the BSe area were higher by approximately 300 mV compared to the BS regions and we concluded that it was mainly due to the difference of the interfacial dipole moment.