Longer Acenes: Synthesis, Interface Formation and Thin Film Stability

01/11/2025 to 31/10/2028

Acenes are polycyclic aromatic hydrocarbons build of linearly fused benzene rings. Shorter acenes with lengths up to pentacene have been used as active materials in optoelectronic devices and have been extensively studied over the last decades. Going towards longer acenes one observes a strong decrease of the HOMO-LUMO gap and an increase in charge carrier mobilities, which qualifies them as organic semiconductors with a high potential for applications. But, their reactivity causes difficulties for synthesis and only recently discovered new synthesis routes have made them available for scientific studies. A possible approach to stabilize the molecular structure, while preserving their excellent electronic properties will be the introduction of fluorine substituents. The aim is a systematic understanding of the growth, geometric and electronic structure of the longer acenes from individual molecules to application relevant film thicknesses. To counter the enhanced reactivity in films, new acene derivatives will be synthesized and studied likewise. The experiments will be accompanied by ab-initio density functional theory(DFT).