Molecular scale insights into the n-type organic semiconducting polymer P(NDI2OD-T2) revealed by scanning tunnelling microscopy

Conjugated polymers are gaining attention for their remarkable conductivity, flexibility, and cost-effective processability, making them ideal for applications in optoelectronics, thermoelectrics, sensors and bioelectronics. The Costantini Group's innovative use of electrospray deposition (ESD) combined with scanning tunnelling microscopy (STM) provides molecular-scale insights into the structure and assembly of surface-adsorbed conjugated polymers. This technique enables the controlled soft-landing of macromolecules on clean single-crystal surfaces, revealing detailed information on polymer assembly, stacking, and conformation. The present study focuses on the structural properties of P(NDI2OD-T2), a prototypical n-type semiconducting polymer, where STM measurements provide critical information on its sequence, backbone conformation and assembly in 2D layers. In particular, our findings show a correlation in the conformation of the repeat units in neighbouring backbones and a well-defined, ordered packing pattern.