High-Performance Photodetectors Based on MoTe₂-MoS₂ van der Waals Heterostructures

Two-dimensional (2D) materials have got extensive attention for multifunctional device applications in advanced nanoelectronics and optoelectronics, such as field-effect transistors, photodiodes, and solar cells. In our work, we fabricated MoTe₂-MoS₂ van der Waals heterostructure photodetectors with great performance using the mechanical exfoliation method and restack technique. It is demonstrated that our MoTe₂-MoS₂ heterostructure photodetector device can operate without bias voltage, possessing a low dark current (10 pA) and high photocurrent on/off ratio (>10⁴). Importantly, the room temperature photoresponsivity of the MoTe₂-MoS₂ photodetector can reach 110.6 and 9.2 mA W^-1 under λ = 532 and 1064 nm incident laser powers, respectively. Our results indicate that the van der Waals heterostructure based on 2D semiconducting materials is expected to play an important role in nanoscale optoelectronic applications.