1 definition

• 结构有序
• 二维平面生长
• 第三维度超薄

单层未必最好，也许几层更佳

2 Graphene family:

• Graphene, Fluorographene, graphene oxide
• hBN white graphene
• BCN, g-CN
• X-enes (silicene. germanene. stanene) borophene. phosphorene, single-element 2D materials

3 2D chalcogenfdes

• MoS₂, WS₂, MoSe2, WSe
• Semiconducting dichalcogenides: MoTe₂, WTe₂, ZrS₂, ZrSe₂ and so on
• Metallic dichalcogenides: NbSe₂, NbS₂, TaSe TiS₂, NiSe₂ and so on
• Layered semiconductors: GaSe. GaTe. 1nSe. Bi₂,Se₃, and so on

4 2D oxides

• Layered Cu oxides
• MoO₃, WO₃, TiO₃, Mn0₂, V₂O₅, TaO₃,. RuO₂ and so on
• Perovskite-type: LaNb₂O₇, (Ca,Sr)₂Nb₃O₁₀, Bi₄Ti₃O₁₂, Ca₂Ta₂TiO₁₀, etc

5 Transition metal carbides:

• Ti₃C₂, Ta₄C₃, etc

6 Hydroxides:

• Ni(OH)₂, Eu(OH)₂ and so on

7 Two kinds of 2D heterostructures

7.1 Lateral heterostructures

7.1.1 advantages

• Less interface
• Simpler band alignment
• More stable interface
• High quality prepared in lab
• Easier to be used into device

7.1.2 Disadvantages

• Prepared only by CVD

7.2 Vertical

7.2.1 Advantages

• Easy to be prepared

7.2.2 Disadvantages

• Dependent sensitively on the mismatch
• Difficult to control the crystal orientation
• Difficult to be used in device