On the electric conductivity of highly ordered monolayers of monodisperse metal nanoparticles.
Monolayers of colloidally synthesized cobalt-platinum nanoparticles of different diameters characterized by transmission electron microscopy were deposited on structured silicon oxide substrates and characterized by scanning electron microscopy, grazing incidence X-ray scattering, and electric transport measurements. The highly ordered nanoparticle films show a thermally activated electron hopping between spatially adjacent particles at room temperature and Coulomb blockade at low temperatures. We present a novel approach to experimentally determine the particles charging energies giving values of 6.7-25.4 meV dependent on the particles size and independent of the interparticle distance. These observations are supported by finite element method calculations showing the self-capacitance to be the determining value which only depends on the permittivity constant of the surrounding space and the particles radius.
Greshnykh
Denis
D
Institute of Physical Chemistry, University of Hamburg, D-20146 Hamburg, Germany.
Frömsdorf
Andreas
A
Weller
Horst
H
Klinke
Christian
C
D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties
D046911:Macromolecular Substances; D008670:Metals