Growth of Transition Metal Dichalcogenide Monolayers with Chemical Vapor Deposition

The direct-gap property of the semiconducting transition metal dichalcogenide monolayers are attractive for optoelectronics and energy harvesting. Here I would like to discuss the synthetic approach to obtain MoS₂ (WSe₂) monolayer directly on arbitrary substrates using vapor phase reaction between metal oxides and S or Se powders. These layer materials can be transferred to desired substrates, making them suitable building blocks for constructing multilayer stacking structures. The significance of charge movement in the emerging field of 2d heterostructures, and the charge distribution strongly affects the properties of the 2d heterostructures. The interaction between these layer materials are characterized by Raman, PL spectra and Second Harmonic Generation properties. Some possible applications based on these 2d heterostructures including photodetection and DNA detection shall be discussed.