Electron Transport Properties of Two-Dimensional Monolayer Films from Au-P-Au to Au-Si-Au Molecular Junctions**Supported by the National Natural Science Foundation of China under Grant Nos 11374033, 11774030, 51735001 and 61775016, and the Fundamental Research Funds for the Central Universities under Grant No 2017CX10007.

Abstract

We investigate the electronic-transport properties of two-dimensional monolayer films from Au-P-Au molecular junction to Au-Si-Au molecular junction using elastic scattering Green’s function theory. In the process of replacing the P atoms with Si atoms every other line from the middle of monolayer blue phosphorus molecular structure, the substitution of Si atoms changes the properties of Au-P-Au molecular junction significantly. Interestingly, the current value has a symmetric change as a parabolic curve with the peak appearing in Au-Si1P1-Au molecular junction, which provides the most stable current of 15.00 nA in a wide voltage range of 0.70–2.70 V. Moreover, the current–voltage characteristics of the structures indicate that the steps tend to disappear revealing the property similar to metal when the Si atoms dominate the molecular junction.