Ohmic-contacted WSe₂/MoS₂ heterostructures for broadband photodetector with fast response

A broadband photodetector based on WSe2/MoS2 van der Waals heterostructures (vdWHs) contacted to indium tin oxide (ITO) is demonstrated. The spectral response range covers the visible to near-infrared wavelengths. The highest performances of the fabricated device with a responsivity of 1392 mA W-1 and specific detectivity of 7.78 x 10(12) Jones are achieved operating at room temperature under 532 nm. Moreover, the WSe2/MoS2 vdWHs using an ITO electrode with Ohmic contact exhibits a fast response time of 9.6 mu s which is almost 10 times faster than that using an Au/Ni electrode with Schottky contact. These could help to realize the key role of contacts in two-dimensional vdWHs-based photodetectors.