Study of an organic nonlinear optical material for nanoscale data storage by scanning tunneling microscope

In this paper, organic thin films of a nonlinear optical (NLO) material ((E)-1-ferrocenyl-2-(l-methyl-4-pyridiniumyl) ethylene iodide) were prepared by a vacuum deposition method. The typical I–V curve of the film exhibits a favorable room-temperature bistability. Further recording experiments have been performed with a scanning tunneling microscope, which confirmed that the thin film of the donor–π–acceptor NLO material could certainly be applied for nanoscale data storage. The average size of the recorded marks is about 1.5 nm. Mechanism analyses suggest that the formation of the recording dots is due to the local change of electrical property of the thin film, and the intermolecular charge transfer induced by an electric field is proposed as the reason for the change.