fig2

Figure 2. Doping-induced strain for 2D materials. (A) Schematic diagram of covalent nitrogen doping in MoS₂ via N₂ plasma treatment; (B) Raman shift after sequential N₂ plasma exposure for different times; (A-B): quoted with permission from Azcatl et al.^[35]; (C) Schematic of the synthesis of NbS₂ and Nb_xW_1-xS₂ monolayers via a CVD method; (D) Atomic models of three doping configurations; (C-D): quoted with permission from Zhang et al.^[58]; (E) Schematic of Se replacing S from the edge to the center in MoS₂; (F) Lattice constant at different positions as most of the outer S atoms are substituted by Se; (G) Calculation results illustrating the relationship among Se occupation, lattice constant, and substitution barrier; (E-G): quoted with permission from Li et al.^[22]. CVD: Chemical vapor deposition; 2D: two-dimensional.