First-principles study of structure and quantum transport properties of C20 fullerene

Using first-principles density-functional theory and nonequilibrium Green's function formalism for quantum transport calculation, we study the electronic and transport properties of C-20 fullerene molecule. Our results show that the equilibrium conductance of C-20 molecule is near 1G(0). It is found that the I-V curve displays a linear region centered about V=0 and nonlinear behavior under higher bias voltages and an obvious negative differential resistance phenomenon in a certain bias voltage range. The mechanism for the negative differential resistance behavior of C-20 is suggested. The present findings could be helpful for the application of the C-20 molecule in the field of single molecular devices or nanometer electronics. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3159024]