Analysis and Investigation of Electronic Transport Coulomb Blockade in Al68 Based on DFT

Electronic transport properties in an Al cluster are investigated theoretically in this paper. We propose a possible illustration of Coulomb blockade based on variable electrostatic potential (ESP). Density functional theory (DFT) was used to achieve the global minimum structure and wave function for analyzing the ESP and density of states (DOS) of Al-68 in different charged states. Al-68 is able to contain multiple electrons. According to the calculation of systematic energy and surface ESP, respectively, the surface of Al68 presents a 0-6.33 eV ESP barrier after electron injection, which is 0 eV at first. The probability density of flow of electrons was calculated under one-dimensional model with double barriers. Expected results were obtained, containing a nonlinear relationship between J and V and flow density steps. Moreover, an assumption is proposed associated with nonlinear conductance phenomenon of zero-dimensional nanomaterials. Significantly, Al films with different thicknesses were prepared by the low vacuum physical vapor deposition (LVPVD) method, exhibiting novel fluorescent behaviors. In addition, the I-V curve of a 25-nm Al film exhibited two steps at 7 and 27 V, respectively, which meant that the step effect was caused by Coulomb blockade, in accordance with the theoretical calculation.