Our main goal in this project is to get an understanding and control of the structure and the electronic transport through the carboxylate-Cu(110) interface, experimentally and theoretically, and to use these data to build up a molecular device, which is based on the exploitation of the different electron transport paths through these molecules. To reach this main goal we will continue in the following steps:
- Exploration of the influence of the geometry, ordering, and coverage density of carboxylic acids on Cu(110) the electron transport properties, e.g. on the molecule-substrate and intermolecular π-π interactions
- Tuning the HOMO-LUMO gap of the carboxylic acids by use of different substituents or heteroatoms introduced into the aromatic ring
- Investigations of geometry (STM), conductance (STS) and electron-phonon coupling (IETS) accomplished by LEED and XPS to get further information about molecular ordering and nature of molecule-substrate coupling.
- Using this basic data set to predict a carboxylic acid, which is stable in two conductivity states. Investigate these molecules in a self-assembled monolayer and as an isolated molecule embedded in a host-matrix of other molecules (e.g. with internal standard).
- Study different sandwich structures of two carboxylic acids with different HOMO-LUMO gaps intentionally influencing the intermolecular electron transport properties.
- Modify single isolated carboxylic acids “in situ” and thus develop a method to selectively change the functionality of predefined molecules to create an electronic device.
- Exploit the electron transport properties along different paths through the carboxylic acids to build up a molecular device.
In addition the full calculation of the electron transport through the molecules for finite bias voltage can be done using a Green-function method within the framework of a full-potential-linearized-augmented-plane-wave (FLAPW) code(FLEUR).
The theoretical understanding and experimental control of the properties these Cu-carboxylate systems will provide a flexible route to nanoengineering surface and device properties in the nanoscience revolution.
