Electronic properties of single Prussian Blue Analog nanocrystals determined by conductive-AFM

Abstract

We report a study of the electron transport (ET) properties at the nanoscale (conductive-AFM denoted as C-AFM hereafter) of individual Prussian Blue Analog (PBA) cubic nanocrystals (NCs) of CsCo^IIIFe^II, with a size between 15 and 50 nm deposited on HOPG. We demonstrate that these PBA NCs feature an almost size-independent electron injection barrier of 0.41 ± 0.02 eV and 0.27 ± 0.03 eV at the CsCo^IIIFe^II/HOPG and CsCo^IIIFe^II/C-AFM tip, respectively, and an intrinsic electron conductivity evolving from a large dispersion between ∼5 × 10⁻⁴ and 2 × 10⁻² S cm⁻¹ without a clear correlation with the nanocrystal size. The conductivity values measured on individual nanocrystals are up to fifty times higher than those reported on PBA films.