Electrode-Engineered Vertical MoS₂/MoTe₂ Heterostructure for Self-Powered, Rapid, High-Sensitivity Broadband...

This study presents a self-powered photodetector based on a vertically structured MoS₂/MoTe₂ van der Waals heterostructure, where electrode engineering strategies significantly enhance the response speed and sensitivity. Compared to conventional lateral counterparts (response times: 40 ms rise/60 ms fall), the vertical heterostructure employs Ni/Au embedded electrodes to reduce contact resistance and Schottky barriers, combined with Cr/Au asymmetric electrodes to optimize carrier separation efficiency, achieving ultrafast response times of 6.3 μs (rise) and 10.3 μs (fall) with an 80 kHz bandwidth. Under self-powered operation (zero bias), the device exhibits a responsivity of 12 mA/W and a specific detectivity of 3 × 10⁹ cm·Hz^1/2·W^-1 at 637 nm visible light, extending to near-infrared (940 nm) and short-wave infrared (1550 nm) regions. The vertical nanochannels enable low power consumption and voltage-tunable optical communication encryption functionality. This work provides a novel approach to overcoming the limitations of traditional lateral structures in speed and spectral response, advancing the development of miniaturized and multifunctional broadband high-speed photodetection technologies.