A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Local Probe Investigation of Self-Assembled Monolayers
Abstract Characteristic depressions with a diameter of 3 – 7 nm and a depth of 0.2 – 1.0 nm are found in scanning tunneling microscopy (STM) images of self-assembled monolayers (SAM) made from linear alkylmercaptanes on gold (111). High-resolution constant-current images and current response to vertical modulation of the probe (dI/dz) show periodic structures with a molecular spacing that can be correlated with the sulfur √3 × √3 addlattce. Deformation-free topographies of SAMs can be extracted with a deconvolution method when force and force gradient are measured on a constant-current STM contour. Results obtained with a combined STM/scanning force microscope on SAMs show that the characteristic depression pattern found with an STM is an electronic effect. The ratio of current versus the generated third harmonic signal in a scanning surface harmonic microscope changes little in the depressions, suggesting that there the electron transfer mechanism is the same as on the flat part of the monolayer. Depressions in STM images are due to a decrease in molecular density of the monolayer that causes a local reduction of the electron conductance.
Local Probe Investigation of Self-Assembled Monolayers
Abstract Characteristic depressions with a diameter of 3 – 7 nm and a depth of 0.2 – 1.0 nm are found in scanning tunneling microscopy (STM) images of self-assembled monolayers (SAM) made from linear alkylmercaptanes on gold (111). High-resolution constant-current images and current response to vertical modulation of the probe (dI/dz) show periodic structures with a molecular spacing that can be correlated with the sulfur √3 × √3 addlattce. Deformation-free topographies of SAMs can be extracted with a deconvolution method when force and force gradient are measured on a constant-current STM contour. Results obtained with a combined STM/scanning force microscope on SAMs show that the characteristic depression pattern found with an STM is an electronic effect. The ratio of current versus the generated third harmonic signal in a scanning surface harmonic microscope changes little in the depressions, suggesting that there the electron transfer mechanism is the same as on the flat part of the monolayer. Depressions in STM images are due to a decrease in molecular density of the monolayer that causes a local reduction of the electron conductance.
Local Probe Investigation of Self-Assembled Monolayers
Mizutani, W. (author) / Anselmetti, D. (author) / Michel, B. (author)
1993-01-01
6 pages
Article/Chapter (Book)
Electronic Resource
English
STM Investigation of Thiol Self-Assembled Monolayers
| British Library Online Contents | 1998
Dendrimer-Based Self-Assembled Monolayers as Resists for Scanning Probe Lithography
| British Library Online Contents | 1999
Electrochemically Polymerizable Self-Assembled Monolayers
| British Library Online Contents | 1995
Sensor Functionalities in Self-Assembled Monolayers
| British Library Online Contents | 2000
Self-Assembled Monolayers for Molecular Nanoelectronics
| Springer Verlag | 2003