Growth of Highly Crystalline and Large Scale Monolayer MoS 2 by CVD: The Role of substrate Position

Monolayer (ML) molybdenum disulphide (MoS 2 ) is of great interest for the scientific community due to its attractive electronic, optoelectronic and mechanical properties. Synthesis of high quality and large size ML MoS 2 at low cost is still a challenge. Here, the growth of large area (≈5 × 1 mm 2 ) ML MoS 2 on SiO 2 /Si substrate via chemical vapor deposition (CVD) method is reported. It is shown by changing the substrate position w.r.t. MoO 3 precursor, that the quality and size of the ML MoS 2 can be drastically tuned. Raman spectroscopy and transmission electron microscopy are performed in order to ascertain the growth and high crystallinity of MoS 2 . Uniformity of MoS 2 layer is adjudged by Raman mapping while atomic force microscopy is performed to determine the thickness of the layer. Kelvin probe force microscopy is performed on ML MoS 2 to draw the band line up of the material.