Stoichiometry modulated tunable optoelectronic properties of Nb-doped WS₂ synthesized by chemical vapor deposition...

Significant progress has been made in the field of two-dimensional WS₂, yet the precise control of the doping process to achieve desired properties and the interpretation of complex physical phenomena in these novel materials necessitate thorough research. In this study, Nb-doped WS₂ is synthesized using chemical vapor deposition technology, leading to triangular flakes with a side length of 12-20 μm. The X-ray photoelectron spectroscopy analysis indicates that the Nb_W substitution defect functions as an electron acceptor. The interlayer and transverse forces of the Nb-doped WS₂ flake approach 1 nN and 150 pN, respectively. As the doping concentration increases, the valence band maximum energy of Nb-doped WS₂ ranges from 4.06 eV to 4.3 eV. Furthermore, the performance of the photodetector is discussed.