Interfaces with N-Heteropolycycles: Morphologies, Electronic Properties and Dynamics of Electronically Excited States
Subject Area Physical Chemistry of Solids and Surfaces, Material Characterization
Prof. Tegeder - PCI, Uni HD
The goal of the project is to elucidate the adsorption properties, the electron structure and the dynamics of optically excited electronic states in N-heteropolycycles adsorbed on noble metal surfaces and in thin molecular films. Precise insights into these parameters are needed to understand the performance of organic molecule-based (opto)electronic devices. Knowing the electronic and structural properties we will systematically modify the electronic structure and the shape of the molecules to optimize the charge transfer efficiency. To achieve the goals we utilize comprehensive experimental techniques. For the determination of the energetic positions of occupied and unoccupied molecular electronic states (transport levels, optical gaps) as well as excitonic states and the dispersion (charge carrier mobility) of electronic states in N-heteropolycycles at metal surfaces energy- and angle-resolved two-photon photoemission (2PPE) is used. In addition, high resolution electron energy loss spectroscopy (HREELS) allows to gain information about electronic transitions. The energetics and dynamics of electronically excited states will be studied by femtosecond time-resolved 2PPE and second harmonic generation (SHG). The characterization of the adsorption properties will be carried out via vibrational HREELS and scanning tunneling spectroscopy.