Photo-response in 2D metal chalcogenide-ferroelectric oxide heterostructure controlled by spontaneous polarization
The interplay between free and bound charges in two-dimensional (2D) semiconductor/ferroelectric oxide structures is responsible for the unique opto-electrical properties of these structures. In this study, we vertically combined the 2D layered semiconductors MoS2 (n-type) and WSe2 (p-type) with a ferroelectric oxide (PbTiO3) and found that a ferroelectric polarization induced accumulation or depletion in the layered materials. The heterostructures exhibited polarization-dependent charge distribution and pinched hysteresis. We show that polarization at the interface promoted efficient charge separation of photo-generated carriers in the 2D layers. Optical control of electrical transport was effectively achieved in the MoS2 layers. This study potentially opens up new applications for semiconductor/ferroelectric systems in electronic devices.