Development of Novel Two-dimensional Layers, Alloys and Heterostructures

The one-atom-think graphene has fantastic properties and attracted tremendous interests in these years, which opens a window towards various two-dimensional (2D) atomic layers. However, making large-size and high-quality 2D layers is still a great challenge. Using chemical vapor deposition (CVD) method, we have successfully synthesized a wide varieties of highly crystalline and large scale 2D atomic layers, including h-BN, metal dichalcogenides e.g. MoS$_{2}$, WS$_{2}$, CdS, GaSe and MoSe$_{2}$ which belong to the family of binary 2D materials. Ternary 2D alloys including BCN and MoS$_{\mathrm{2x}}$Se$_{\mathrm{2(1-x)}}$ are also prepared and characterized. In addition, synthesis of 2D heterostructures such as vertical and lateral graphene/h-BN, vertical and lateral TMDs are also demonstrated. Complementary to CVD grown 2D layers, 2D single-crystal (bulk) such as Phosphorene (P), WTe$_{2}$, SnSe$_{2}$, PtS$_{2}$, PtSe$_{2}$, PdSe$_{2}$, WSe$_{\mathrm{2x}}$Te$_{\mathrm{2(1-x)}}$, Ta$_{2}$NiS$_{5}$ and Ta$_{2}$NiSe$_{5}$ are also prepared by solid reactions. There work provide a better understanding of the atomic layered materials in terms of the synthesis, atomic structure, alloying and their physical properties. Potential applications of these 2D layers e.g. optoelectronic devices, energy device and smart coating have been explored.