B03 • Boron-Containing Polycyclic Aromatic Hydrocarbons: Synthesis, Surface Science, and Functional Materials for Organic Electronics

Replacement of sp²-hybridized carbon in polycyclic aromatic hydrocarbons (PAHs) by boron affords electron-deficient π-scaffolds due to the vacant p_z-orbital of three-coordinate boron. Based on this simple rationale, the present project relies on boron as an effective electronically perturbing dopant element for organic semiconductors.
In this project, we will develop vacuum-sublimable and solutionprocessable planar boron-containing PAHs (B_n-PAHs) with tunable electronic properties (HOMO, LUMO, band gap) and study their physical properties, self-assembly on surfaces, and their suitability for application in organic electronics. Whilst previous research often relied on the stabilization of boron centers by bulky substituents, we will devote particular effort on the elaboration of synthetic procedures toward planar B_n-PAHs equipped with specific substituents that afford desired packing arrangements for efficient charge and exciton transport in the solid state.
The fundamental structural and local electronic properties of planar, surface-deposited B_n-PAHs and their potential for the realization of one-dimensional boron-doped nanoribbons will be investigated by scanning tunnelling microscopy (STM) and spectroscopy (STS). Based on these findings we will explore the suitability of B_n-PAHs as organic semiconductors in organic field-effect transistors (OFETs), organic light emitting diodes (OLEDs) and organic solar cells (OSCs).