Nanometer-sized multijunction arrays are expected to exhibit a large Coulomb blockade effect. However, up to now, only highly disordered arrays can be fabricated. In this article, we evaluate the consequences of disorder on the dispersion of the device characteristics. We show that, as observed for regular arrays, the threshold voltage Vth increases with the length of the multijunction array. At very low temperature, the Vth dispersion is small. Conversely, at higher temperature, a large dispersion in Vth is observed. We evidence the importance of the different array parameters with respect to the device characteristics. We show that the crucial parameters are the tunnel resistances and, therefore, for a two-dimensional array, the total resistance of the minimal resistance path is the most relevant parameter.

In recent years, a lot of attention has been paid to carbon nanotube (CNT) networks and their applications to electronic devices. Many studies concentrate on the percolation threshold and the characterization of the conduction in such materials. Nevertheless, no theoretical study has yet attempted to characterize the CNT features inside finite size CNT networks. We present a theoretical approach based on geometrical and statistical considerations. We demonstrate the possibility of explicitly determining some relations existing between two neighbor CNTs and their contact efficiency in random networks of identical CNTs. We calculate the contact probability of rigid identical CNTs and we obtain a probability of 0.2027, which turns out to be independent of the CNT density. Based on this probability, we establish also the dependence of the number of contacts per CNT as a function of the CNT density. All the theoretical results are validated by very good agreement with Monte Carlo simulations.

In this paper, we report on a process to prepare gold nanoparticle stripes on SiO(2) by convective/capillary assembly without any patterning of the substrate. Electrical devices were then fabricated using stencil lithography in order to avoid any contamination. I(V) measurements at room temperature show that these stripes have an ohmic behavior between +/- 0.5 V with a resistivity ranging from one to two orders higher than the gold bulk value. Furthermore, I(V) and I(t) measurements reveal current fluctuations that were interpreted in terms of charging and discharging of nanoparticle islands leading to a very large electrostatic perturbation of current conduction paths. Unconventional relative amplitudes of up to 99% RTS fluctuations were observed.

The purpose of this paper is to study single electron charging of a floating gate composed of nanocrystals in a metal-oxide-semiconductor transistor. We present a three-dimensional model of electron tunneling into quantum islands that are spherical in shape. This model can be numerically solved through a two-dimensional finite element approach. In this way, extensive and accurate numerical experimentations can be carried out due to the reduced computer time cost. The curves of tunneling time versus bias voltage exhibit complex serrated shapes, related to both the energy subbands of the channel and the energy states of the nanocrystal. The results are discussed for different channel doping densities.

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The temperature behavior of multiple tunnel junction (MTJ) devices made with sub-5-nm gold islands is investigated. A smooth decrease of the Coulomb gap with increasing temperatures is observed. The critical temperature beyond which the Coulomb blockade effect is suppressed is found to change as a function both of the average size of the islands and of the size of the two-dimensional (2D) array of islands forming the MTJ. This latter property is attributed to the role of disorder in the 2D array. Results are compared with Monte Carlo simulations of current transport through highly disordered 2D arrays which reproduce the experimental evolution of the Coulomb gap with temperature.