Room Temperature Hydrogen Sensor Based on Single-Electron Tunneling Between Palladium Nanoparticles

In this paper, we present the results of single-electron tunneling in two-dimensional (2D) hexagonal closed packed arrays of palladium nanoparticles. After inspecting the emergence of Coulomb blockade phenomena, we demonstrate the possibilities of using these arrays as a single-electron tunneling based hydrogen sensor. We assumed arrays of palladium nanoparticles with diameters of 3.5 and 6 nm based on the arrays synthesized experimentally. Using SIMON simulator, we obtained IV characteristics of equivalent circuits, consisting palladium nano-islands and tunneling junctions between source-drain electrodes, before and after exposing to hydrogen gas at room temperature. Resistance and capacitance of tunneling junctions were calculated according to the lattice parameter expansion of palladium nanoparticles at different pressures of hydrogen gas. We observed the change in the total resistance of the device before and after exposure to hydrogen. The obtained results indicate that this configuration show single-electron tunneling and can be used as the hydrogen gas sensor. This sensor can detect concentrations as low as 1.3% in air which is less than ammability concentration.