Figure 2.

A brief overview of the recent progress made toward CVD growth of TMD HSs, including vertical, lateral, and hybrid configurations.

(A) A proposed growth sequence of NbS₂ on top of MoS₂. NbS₂ first nucleated at the corner on MoS₂ and migrated at the edges having full coverage of the bottom layer of MoS₂ (Fu et al., 2018). Copyright 2018, American Chemical Society.

(B) A schematic of a vertical MTe₂ (M = V, Nb, Ta) on the WX₂ (X = SE, S) layer (Wu et al., 2019c). Copyright 2019, Wiley.

(C) Schematic representation of multilayer Bi₂Te₃ on top of 1L-WSe₂ (Yang et al., 2020). Copyright 2020, American Chemical Society.

(D) Atomic ball model for NiTe₂/MoS₂ vertical heterostructure synthesized via two-step CVD process (Zhai et al., 2020). Copyright 2020, American Chemical Society.

(E) Composite PL-map of three-junction MoS₂-WS₂ (top left) and five-junction of MoSe₂-WSe₂ (bottom left) lateral heterostructures. Normalized PL contour plot (colored) along a perpendicular to the interfaces corresponding to the three-junction MoS₂-WS₂ (Sahoo et al., 2018). Copyright 2018, Springer Nature.

(F) SEM images of WS₂-WSe₂ superlattices (Xie et al., 2018). Copyright 2018, AAAS.

(G) Schematic for bilayer lateral heterostructure (top left). A PL position mapping (bottom left) and HAADF-STM image (middle) corresponding to MoS₂-WS₂ bilayer lateral heterostructure. An optical image of bilayer multi-junction MoS₂-WS₂ lateral heterostructure is shown with the scale bar of 10 μm (Sahoo et al., 2019). Copyright 2019, American Chemical Society.

(H) Persistence photoconductivity mapping of WS₂-MoS₂ multi-junction lateral heterostructure (left), and (right) microwave real part of conductance signal (S_G) of the channels with the increasing energy of excitation photon (1.75 and 1.97 eV) (Berweger et al., 2020). Copyright 2020, American Chemical Society.

(I) (left) Polarization dependence second harmonic generation (SHG) and (right) the corresponding SHG intensity maps of the single-layer MoSe₂-WSe₂ lateral heterojunction collected at 455 nm emission wavelength (Sousa et al., 2021). Copyright 2021, IOP.

(J) An atomic model of thin-film hybrid structure of WS₂/WS₂-MoS₂ (Zhang et al., 2018). Copyright 2018, IOP.

(K) Schematic of VSe₂ and TMDs hybrid structure where multilayer VSe₂ was grown at the edges of 1L-TMDs followed by coverage of top layer via two-step CVD process (Zhang et al., 2019b). Copyright 2019, American Chemical Society.