Growth process of molybdenum disulfide thin films grown by thermal vapour sulfurization

Abstract

Thermal vapour sulfurization is a straightforward method which transforms the spin-coated MoS-based film into MoS2 thin film. The inhomogeneous surface morphology of deposited MoS2 thin film changed to homogeneous with lower pinhole density. Also, the emergence of MoS2(002) X-ray diffraction peak can be seen after the sulfurization process. X-ray photoelectron spectroscopy showed the early formation of MoS2 bonding at baking stage with the detection of Mo4+ 3d and S2− 2p core levels. However, the existence of other charges state of Mo 3d before the sulfurization process, indicated that a minimal amount of molybdenum oxide compounds was present. At the sulfurization stage, the difference between Mo 3d5/2 and S 2p3/2 photoelectron lines of 67.2 eV was observed which shows the high formation of MoS2 crystallite. The absorption properties of MoS2 were detected at ~ 667 nm, ~ 617 nm, and ~ 442 nm. Next, the resonant Raman spectrum estimates the multilayers of MoS2 were grown. Also, the existence of LA(M) indicates the presence of structural defects and nanoparticle features of MoS2. High-resolution transmission electron microscopy revealed the growth of vertically aligned MoS2 planes, namely edge-terminated phenomenon. Polycrystalline quality of MoS2 was determined by selective area electron diffraction.