Geometric Structure Modulate the Transport Properties of 1,4-Benzenediamine Junction: First-Principle Calculations Bin Ouyang ^{1*}, Yu-Chang Chen^{1}^{1}Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan* presenting author:Ben OuYang, email:a15013515@gmail.com In the previous researches, the 1,4-Benzenediamine junctions are extensively studied in the experiments, however, these values of conductance quantum are different. This reason may be due to the geometric structures between the molecules and the electrode, which leads to contact resistance. In this study, we investigate the conductance with relation to the change of the distance and angle between the molecules and the electrode. We apply first principle calculations where the Lippmann-Schwinger equation allied with density functional theory. The interaction between the molecules and the electrode are dominated by the van der Waals' force, because the 1,4-Benzenediamine is a stable molecule. This results implied that the density of states of these systems are similar, where there charge transfer occurs in the contact region. Nevertheless, the energy spacing between LUMO (HOMO) and Fermi level strongly depends on the distance and angel, which lead to significant change in the values of the conductance. Finally, our theoretical results are expected to be comparable with the previous experiments.
Keywords: 1,4-benzenediamine, First-Principles |