USING OF SEEDING PROMOTERS AND PATTERNED TO GROWTH LARGE-SCALE OF HIGH-QUALITY TUNGSTEN DISULFIDE

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have been the focus of intense research due to their remarkable electronic and optoelectronic properties, which include a unique indirect-to-direct bandgap transition with reducing layer numbers, high carrier mobility and strong spin-orbital coupling due to broken inversion symmetry. These interesting properties make 2D TMDCs particularly well suited to be used in electronic and optoelectronic devices.

The integration of such atomic layers into functional devices will depend on the ability for their rational growth with the desired number of layers, domain size, chemical composition, etc. Here we use chemical vapor deposition (CVD) methodologies to study the growth of WS₂. In this scheme, we study the nucleation and growth of such material at the single-layer level combining between the so-called “seeding promoters” and seeded-growth methodologies. The first consist of pre-coating the growth substrate with aromatic molecules that were shown to increase the domain size. The seeded-growth methodology is carried out by pre-patterning the growth substrate with “seeds” that act as nucleation sites, and therefore, allows a better control on the nucleation and growth. The use of different precursors will be described as well and growth differences highlighted.

These studies are expected to lead to a better basic understanding of the growth process and thus, improve it for large-scale synthesis of high quality 2D materials.