Temperature evolution of multiple tunnel junction devices made with disordered two-dimensional arrays of metallic islands

The temperature behavior of multiple tunnel junction (MTJ) devices made wit h sub-5-nm gold islands is investigated. A smooth decrease of the Coulomb g ap with increasing temperatures is observed. The critical temperature beyon d which the Coulomb blockade effect is suppressed is found to change as a f unction 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 wi th Monte Carlo simulations of current transport through highly disordered 2 D arrays which reproduce the experimental evolution of the Coulomb gap with temperature. (C) 1999 American Institute of Physics. [S0003-6951(99)02020- 3].