Titre :

Experimental observation of the role of countercations on the electrical conductance of Preyssler-type polyoxometalate nanodevices

Auteur(s) :

Huez, Cécile [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Nanostructures, nanoComponents & Molecules - IEMN [NCM - IEMN]
Renaudineau, Séverine [Auteur]
Edifices PolyMétalliques [E-POM]
Institut Parisien de Chimie Moléculaire [IPCM]
Volatron, Florence [Auteur]
Edifices PolyMétalliques [E-POM]
Institut Parisien de Chimie Moléculaire [IPCM]
Proust, Anna [Auteur]
Edifices PolyMétalliques [E-POM]
Institut Parisien de Chimie Moléculaire [IPCM]
Vuillaume, Dominique [Auteur correspondant]
Nanostructures, nanoComponents & Molecules - IEMN [NCM - IEMN]

Titre de la revue :

Nanoscale

Pagination :

10634-10641

Éditeur :

Royal Society of Chemistry

Date de publication :

2023-05-09

ISSN :

2040-3364

Discipline(s) HAL :

Physique [physics]
Chimie

Résumé en anglais : [en]

Polyoxometalates are nanoscale molecular oxides with promising properties that are currently explored for molecule-based memory devices. In this work, we synthesize a series of Preyssler polyoxometalates (POMs), ...
Lire la suite >Polyoxometalates are nanoscale molecular oxides with promising properties that are currently explored for molecule-based memory devices. In this work, we synthesize a series of Preyssler polyoxometalates (POMs), (Na-P5W30O110)14-,stabilized with four different counterions, H+, K+, NH4+ and tetrabutylammonium (TBA+), and we study the electron transport properties at the nanoscale (conductive atomic force microscopy, C-AFM) of molecular junctions formed by self-assembled monolayers (SAMs) of POMs electrostatically deposited on ultraflat gold surface prefunctionalized with a positively charged SAM of amine-terminated alkylthiol chains. We report that the electron transport properties of P5W30-based molecular junctions depend on the nature of the counterions, the low-bias current (in the voltage range -0.6 V to 0.6 V) gradually increasing by a factor ca. 100 by changing the counterion in the order K+, NH4+, H+ and TBA+. From a statistical study (hundreds of current-voltage traces) using a simple analytical model for charge transport in nanoscale devices, we show that the energy position of the lowest unoccupied molecular orbital (LUMO) of the P5W30 with respect of the Fermi energy of the electrodes increases from ca. 0.4 eV to 0.7 eV and that that electrode coupling energy also increases from ca. 0.05 to 1 meV in the same order from K+, NH4+, H+ to TBA+. We discuss several hypotheses on the possible origin of these features, such as a counterion-dependent dipole at the POM/electrode interface and counterion-modulated molecule/electrode hybridization, with, in both cases, the largest effect in the case of TBA+ counterions.Lire moins >

Langue :

Anglais

Vulgarisation :

Non

Commentaire :

Preprint: full text, figures and supporting information

Collections :

• Institut d'Électronique, de Microélectronique et de Nanotechnologie (IEMN) - UMR 8520

Source :

Harvested from HAL