2D WS2(Yb)/3D Te Mixed-Dimensional Van der Waals p-p Heterostructure with High Optoelectronic Performance

Mixed-dimensional van der Waals heterostructures (vdWHs) have aroused extensive attention owing to distinctive properties by integrating advantages of materials with different types and dimensionalities for high-performance optoelectronic devices. Herein, 2D Yb-doped monolayer WS2 (WS2(Yb)) nanosheets and 3D bulk Te microwires are first prepared using chemical and physical vapor deposition (CVD/PVD) techniques, respectively. 12.7 at% of Yb-doping concentration in WS2(Yb) matrix is achieved. Te microwires are transferred onto WS2(Yb) triangles by microarea fixed-point dry transfer technique to form 2D WS2(Yb)/3D Te p-p heterostructures with a clean interface. Both p-type semiconductors are shown for WS2(Yb) monolayer and bulk Te by calculating their band structures based on density functional theory (DFT), which is consistent with the experimental results. The optoelectronic device based on the WS2(Yb)/Te mixed-dimensional vdWHs is fabricated using Au/Cr as the electrodes. Further, the photodetector demonstrates outstanding optoelectronic performance, including 1.87 A W-1 of responsivity, 366.7% of external quantum efficiency, and 2.53 x 10(11) Jones of specific detectivity under illumination of a 635 nm light. Here a remarkable strategy is provided for preparation of mixed-dimensional optoelectronic devices with high performances.