Light-induced negative differential resistance effect in a resistive switching memory device

The negative differential resistance (NDR) effect was observed in a Pt/BiFeO3/TiO2/BiFeO3/Pt memory cell by using light-illumination as extra stimulation. Further, the coexistence appearances and gradually becomes obvious when the device is exposed to light-illumination, which display an excellent stability and reversibility of the coexistence of NDR and resistive switching (RS) at room temperature. Through analysis of the physical conduction mechanism, it is expected that a large number of photo-generated charge carriers are induced under light-illumination on the surface and interface of the heterojunction is responsible for the appearance of this coexistence phenomenon. Importantly, the NDR effect is strengthened by the competition transfer of charge carrier in the polarized electric field under light-illumination. This work shows that the coexistence of light-modulated NDR and RS can deeply explore the potential applications of light-controlled multifunctional devices.