Theoretical investigation of the O2 adsorption effect in the electron transport of single Fe-porphyrin molecule

The effect of O2 adsorption on the electron transport behavior of Fe-porphyrin molecule is investigated by the first-principles computational approach. The current–voltage characteristics of Fe-porphyrin and O2 adsorbed Fe-porphyrin between gold electrodes are calculated. We find that the conductance of the Fe-porphyrin decreases dramatically upon the adsorption of O2, which suggests that this system has potential application as a molecular sensor or a switch. This switching-behavior is analyzed from the evolutions of the transmission spectra and the molecular projected self-consistent Hamiltonian states of the molecular systems.