Charge transport in percolating network of bimetallic nanoclusters

A.I. Ayesh, S.T. Mahmoud, N. Qamhieh
United Arab Emirates University, AE

Keywords: PdCu, bimetallic nanoclusters, nanocluster devices, inert–gas condensation, tunneling, charge transport

Summary:

Transport of charge carriers in percolating nanocluster devices based on bimetallic PdCu nanoclusters is investigated in this work. The device is fabricated by self–assembly of nanoclusters between electrical electrodes inside an ultra–high vacuum compatible system. The average size of the produced nanoclusters is 7.3 nm, and the composition is Pd0.77Cu0.23. Systematic in–situ current–voltage measurements as a function of temperature were performed which provide a conductance–temperature profile. The results are explained in terms of the charge carriers’ tunneling through small potential barriers at the junctions between nanoclusters. The results predict the size of nanoclusters as well as the magnitude of the potential difference of the tunneling barriers. This investigation helps understanding the nature of the interface between nanoclusters and the charge carrier transport within those devices to be utilized for optimizing gas sensing properties of PdCu nanocluster devices.