Effect of the orientation of nitro group on the electronic transport properties in single molecular field-effect transistors.

Molecular devices with nitro groups display unique electronic transport properties in experiments. By applying the non-equilibrium Green's function combined with density functional theory, we find that the orientation of the nitro group with respect to the backbone of the molecule has a crucial effect on the device performance and can show unusual experimental phenomena. Furthermore, molecular devices with a nitro group are sensitive to gate voltage and suitable for making effective single molecular field-effect transistors. These results provide an important theoretical support to experiments and the design of future molecular devices by using nitro groups.