Fig 1

Graphene and the FET based on it 19, 22. (a) Schematic view and scanning electron microscope image of the device based on graphene, Adapted from American Association for the Advancement of Science publisher; (b) Resistivity (ρ), conductivity (σ) and carrier concentration (n0) of few-layer graphene, Adapted from American Association for the Advancement of Science publisher; (c) Lattice structures and band structures at the corners of the first Brillouin zone for monolayer graphene, Adapted from Nature Publishing Group publisher. "

Fig 2

Schematic illustration of TMDs atom structure and the energy band structure of MoS2 22, 58. (a) Schematic of a typical MX2 structure and the structural polytypes: 2H, 3R, 1T, Adapted from Nature Publishing Group publisher; (b) The band structure of monolayer molybdenum disulfide, Adapted from Nature Publishing Group publisher. "

Fig 3

Schematic illustration of BP atom structure, band diagram and anisotropic property 22, 67, 76. (a) Atomic structure of black phosphorus, Adapted from Nature Publishing Group publisher; (b) The band structure of BP, Adapted from Nature Publishing Group publisher; (c) Orthogonality between the dominant heat and electron transport directions in single-layer BP, Adapted from American Chemical Society publisher. "

Fig 4

The fabrication of vdWHs structure and its electrical properties 87, 89. (a) The fabrication of vdWHs by mechanically assembled stacks, Adapted from American Association for the Advancement of Science publisher; (b) The atom and energy band structures of MoS2/BP, Adapted from American Chemical Society publisher. "

Fig 5

Schematic illustration of 2D layered material system 22. Adapted from Nature Publishing Group publisher. "

Fig 6

FETs based on TMDs 97, 103. (a) Three-dimensional schematic view of single layer MoS2 FET, Adapted from Nature Publishing Group publisher; (b) Chemical p-doping of single layered WSe2 by NO2, Adapted from American Chemical Society publisher "

Fig 7

Schematic illustration of fabrication of pn junction based on TMDs with different methods 104-106. (a) Electrostatic doping, Adapted from Nature Publishing Group publisher; (b) Chemical doping lateral pn junction, Adapted from American Chemical Society publisher; (c) Chemical doping vertical pn junction, Adapted from American Chemical Society publisher. "

Fig 8

BP-based FETs 24, 67, 107, 108, 111 (a) Single layer BP FETs, Adapted from Nature Publishing Group publisher; (b) The channel length effect and electrode material on performance of BP FETs, Adapted from American Chemical Society publisher; (c)Short-channel BP transistor with 20nm channel length, Adapted from American Chemical Society publisher; (d) Monolayer atomic crystal molecular super lattices, Adapted from Nature Publishing Group publisher; (e) The anisotropic property of BP FETs, Adapted from American Chemical Society publisher. "

Fig 9

The pn junction and protection layer for BP transistor 113, 116. (a) Electrostatic doping method of pn junction, Adapted from Nature Publishing Group publisher; (b) Few-layer BP FETs under protection of Al2O3, Adapted from American Chemical Society publisher. "

Fig 10

The 2D lateral vdWHs FETs 120, 121, 123. (a) Graphene-BP, Adapted from American Chemical Society publisher; (b) WSe2/MoS2, Adapted from Nature Publishing Group publisher; (c) BP/MoS2, Adapted from American Chemical Society publisher. "

Fig 11

The 2D vertical vdW FETs 126-128. (a) Graphene-MoS2-Graphene, Adapted from Nature Publishing Group publisher; (b) Graphene-MoS2-Ti, Adapted from Nature Publishing Group publisher; (c) Graphene-BP-Au, Adapted from American Chemical Society publisher. "

Fig 12

Special functional electronic devices based on two-dimensional semiconductor materials 131, 132, 136. (a) Bilayer MoS2 integrated circuit, Adapted from American Chemical Society publisher; (b) WSe2-based COMS, Adapted from American Chemical Society publisher; (c) MoS2-based memristors, Adapted from Nature Publishing Group publisher. "

Fig 13

MoS2-based photodetector 139, 141, 143. (a) Monolayer MoS2 photodetector, Adapted from American Chemical Society publisher; (b) Thickness dependent photodetector, Adapted from American Chemical Society publisher; (c) Ultra-sensitive MoS2 photodetector, Adapted from Nature Publishing Group publisher. "

Fig 14

The different enhancement methods of MoS2-based photodetector 145, 147, 156. (a) Laser micromachining, Adapted from American Chemical Society publisher; (b) Encapsulated by HfO2, Adapted from American Chemical Society publisher; (c) Au plasmon electrode-enhanced photodetector, Adapted from American Chemical Society publisher. "

Fig 15

BP-based photodetector 157, 158, 163. (a) Monolayer BP photodetector, Adapted from American Chemical Society publisher; (b) Wavelength dependent photocurrent, Adapted from American Chemical Society publisher; (c) Three-dimensional Integration of black phosphorus photodetector with silicon photonics and nano-plasmonics, Adapted from American Chemical Society publisher. "

Fig 16

Graphene/2D semiconductor/Graphene photodetector165-167. (a) Graphene/WS2/Graphene, Adapted from American Association for the Advancement of Science publisher; (b) Graphene/MoS2/Graphene, Adapted from Nature Publishing Group publisher; (c) Graphene/MoS2/Graphene, Adapted from Nature Publishing Group publisher. "

Fig 17

Vertical heterojunction photodetector 174, 178 (a) BP/MoS2, Adapted from American Chemical Society publisher; (b) MoS2-graphene-WSe2, Adapted from American Chemical Society publisher. "