Optically Controllable 2D Material/Complex Oxide Heterointerface

Heterostructures play a vital role in functional devices on the basis of the individual constituents. Non‐conventional heterostructures formed by stacking 2D materials onto structurally distinct materials are of great interest in achieving novel phenomena that are both scientifically and technologically relevant. Here, a heterostructure based on a 2D (molybdenum ditelluride) MoTe(2) and an amorphous strontium titanium oxide (a‐STO) thin film is reported. The heterostructure functions as a high‐performance photodetector, which exhibits anomalous negative photoresponse in the pristine device due to the scattering effect from the light‐induced O(δ‐) ions. The photoresponsivity and the specific detectivity are found to be >10(4) AW(‐1) and >10(13) Jones, respectively, which are significantly higher than those in standard MoTe(2) devices. Moreover, through tuning the light programming time, the photodetection behavior of the MoTe(2)/a‐STO heterostructure experiences a dynamic evolution from negative to positive. This is due to the optically controllable modulation of the interfacial states, which is further confirmed by the X‐ray photoelectron spectroscopy and photoluminescence measurements. It is envisioned that the 2D material/a‐STO heterostructure could be a potential platform for exploring new functional devices.