Tuning Coulomb blockade in ultra-small metallic nanoparticle self-assemblies, at room-temperature

Tuning Coulomb blockade at room temperature in nanoparticle self-assemblies can open the door to the development of a new class of nano-electronics. Here, we describe self-assemblies of ultra-small platinum nanoparticles, the morphology and electrical properties of which can be tuned through slight modifications of their aryl-or alkyl thiol ligand backbones or chain length. Three parameters have been modified independently at an unprecedented fine level to control the Coulomb blockade energy: the size of the nanoparticles (between 1.2 and 1.7 nm), the distance between them (between 1.9 and 2.5 nm) and the dielectric constant of the ligands (between 2.7 and 7.1). Elaborating such systems, stable in air for months, and understanding their electrical properties are first steps towards nanoelectronic systems where the charging energy of the nanoparticles can be tuned by the nature of the ligands.