Effects of Contact Geometry on Electron Transport of 1,4-Diaminobenzene

The equilibrium electron transport of 1,4-diaminobenzene sandwiched between two Au electrodes is simulated by using a first principles analysis. The results show that equilibrium conductance increases with the molecule-electrode distance decreasing, and a platform occurs at the distance varying from 1.4A to 1.9A, implying the insensitiveness of 1,4-diaminobenzene equilibrium conductance to molecule--electrode distance. This is helpful to understand the improved reliability and reproducibility of conductance measurements using amines.