2D Nanomaterials

Two-dimensional (2D) materials are a class of materials that are only a few atoms thick, typically consisting of a single layer of atoms arranged in a specific pattern. The unique properties of these materials arise from their reduced dimensionality, which leads to unusual electronic, optical, and mechanical characteristics.Because of their characteristics, the 2D material has attracted considerable interest as a potential candidate for transparent and flexible electrodes, transparent and ultra-thin piezoelectric devices, and energy harvesting applications

1) Large-Area Synthesis of 2D Materials

To achieve successful 2D material-based applications, it is essential to enable large-scale and high-quality growth of 2D materials, establish residue-free transfer processes, and facilitate direct growth of various 2D materials on other 2D layer substrates. In this study, we have conducted an investigation into the high-quality and large-scale growth of graphene, MoS2, h-BN, TMDs, and heterostructures of 2D materials using the chemical vapor deposition (CVD) growth method.

Schematic image of MoS2 growth through Sputter & CVD

Large-area synthesis of monolayer MoS2

Synthesis of h-BN layer growth

2) Layer Control via Phase-Transition-Induced Growth

The phase-transition-induced growth method has been found effective in synthesizing layer-controlled and electronic-state-modulated MoS2 films with excellent uniformity on a wafer scale. By adjusting the amount of Mo atoms in the initial deposition, the number of layers can be controlled, and this method is applicable to both intrinsic and heteroatom-inserted MoS2. Nb insertion in MoS2 films causes changes in the electronic states and work function. Thicker MoS2 films have lower activation energy for Nb insertion, making electronic state modulation easier.

Schematic image of MoS2 growth through Sputter & CVD

3) Synthesis of Point-Defect-Passivated MoS2 Nanosheet

The sulfur (S) vacancy passivation on a monolayer MoS2 greatly affects to its piezoelectricity. The S treatment process effectively passivates S vacancies on the MoS2 surface, leading to reduced charge-carrier density and preventing the screening effect of piezoelectric polarization charges

Schematic image of MoS2 growth through Sputter & CVD