MOST Molecules: From Single-Molecule Studies to Low-Dimensional Nanostructures via On-surface Synthesis

• Applicant: Dr. Suchetana Sarkar
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 584674685

The transition to renewable energy requires efficient storage solutions that can capture solar energy, hold it over long timescales, and release it on demand. Molecular Solar Thermal (MOST) systems provide such a strategy by combining absorption, storage, and release functions within one molecule. Among them, the norbornadiene (NBD)–quadricyclane (QC) system is particularly promising due to its high energy density and reversible isomerization. Yet, while switching has been extensively studied in solution and less so on metal surfaces, little is known about its behaviour on wide-band gap or insulating substrates—surfaces that are essential for device integration. This project pioneers the study of NBD derivatives on metal oxide supports, using advanced low-temperature scanning probe microscopy under ultrahigh vacuum. The first goal is to characterize adsorption and reversible switching on TiO₂ and Al₂O₃. The second is to perform on-surface synthesis of covalently linked NBD-based polymer chains and assess whether cooperative switching persists in extended nanostructures. Finally, electronic transport measurements in STM-based junctions will directly link structural switching to electronic response. This project addresses the gap between fundamental model studies on metal surfaces and the more relevant oxide surfaces, thereby contributing to the future integration of MOST systems into functional nanostructures.

• DFG Programme: Position