Synthesis and Heterostructures of Monolayer Semiconductors
Yi-Hsien Lee1*
1Materials Science and Engineering, National Tsing Hua University (NTHU), Taiwan
* presenting author:Yi-Hsien Lee,
Monolayers of layered transition metal dichalcogenides (TMD), such as MX2 (M=Mo, W and X=S, Se), offered a burgeoning field in fundamental physics, energy harvesting, electronics and optoelectronics. Recently, atomically thin heterostructures of semiconducting monolayers with various geometrical and energy band alignments are the key materials for next generation flexible nano-electronics. The individual TMD monolayers can be adjoined laterally or vertically to construct in-plane or vertical heterostructures, which are difficult to reach with the laborious pick-up-and-transfer method of the exfoliated flakes. The ability to produce copious amounts of high quality layered heterostructures on diverse surfaces is highly desirable but it has remained a challenging issue. Here, we have achieved a direct synthesis of various heterostructures of semiconducting monolayers using chemical vapor deposition (CVD) with the seeding promoter of aromatic molecules. The symmetry and the interface of these heterostructures were examined using some optical analysis and atomic-resolution scanning TEM techniques. The growth, characterizations and applications of monolayer semiconductors and their heterostructures would be presented.

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Keywords: 2D materials, Heterostructure , CVD, MoS2