Abstract
The proximal coupling between graphene and transition-metal-oxide heterostructures may integrate their unique features and further generate emergent states. Using the photoconductivity of graphene as an effective probe, we demonstrate the existence of a built-in polar field within the layer of the heterostructures for both conducting and insulating interfaces. Such a polar field is a prerequisite for the validity of the electronic reconstruction mechanism for the interfacial conductivity. The built-in polar field is reflected by the hole doping in the graphene in proximity to the induced by pulsed deep-ultraviolet illumination regardless of the graphene’s carrier type. These photoresponse characteristics also render the hybrid system a convenient deep-ultraviolet sensor. Moreover, we design an efficient broad-spectrum photodetector benefiting from the large in-plane electric field in graphene across the boundary between the and . Our findings may provide clues to the design of photosensors based on the hybrid structures of graphene and oxide heterostructures.
- Received 25 December 2015
DOI:https://doi.org/10.1103/PhysRevApplied.6.014005
© 2016 American Physical Society