2, University of Wisconsin-Madison, Madison, Wisconsin, United States
3, University of Luxembourg, Luxembourg, , Luxembourg
4, Luxembourg Institute of Science and Technology, Luxembourg, , Luxembourg
Due to their switchable polarization, ferroelectric materials have been used to modulate the electronic transport properties of two-dimensional (2D) semiconductors. Polarization reversal in ferroelectrics is typically realized via application of an electric field. Recently, it has been demonstrated that mechanical stress and change of chemical environment could also induce the polarization switching. In this work, we have demonstrated the optically-induced polarization switching in the hybrid MoS2/BaTiO3/SrRuO3 tunnel junctions, which is realized via photo-absorption in 2D MoS2. We have found that the switching time of the heterostructure highly depended on the light intensity. Based on the DFT (Density Function Theory) simulations, we attribute the optically-induced switching to the light absorption in the MoS2 electrode via the dominant intra-layer excitons that eventually decay into inter-layer excitons resulting in the interfacial charge favoring polarization reversal. The observed effect should be a common phenomenon for the 2D/ferroelectric heterostructures, which would provide a viable way to modulate the functional properties of ferroelectric-based electronic devices remotely through optical illumination.