Impact of water vapor on the 2D MoS2 growth in metal-organic chemical vapor deposition

In the presented work, the method of metal–organic chemical vapor deposition (MOCVD) using Mo(CO)6 and H2S assisted by oxidative etching with water vapor, was employed for the synthesis of MoS2. This study was aimed at detailed investigation of the films' properties obtained via this method and identifying methods for elimination of such disadvantages as the carbon impurities and the small size of crystalline domains in the films. It was found that in the temperature range from 850 °C to 950 °C, the effect of water vapor on the morphology of MoS2 is significantly different. The study of the chemical states of molybdenum and sulfur made it possible to associate the size of the crystal domains formed with the efficiency of removing the oxidized states of Mo6+ and S6+. It is assumed that the increase in the domains’ size is due to rapid lateral growth, resulting from the complete removal of the oxidized states at the edges, as well as a decrease in the density of nucleation centers due to the etching of less stable seeds on the substrate surface. •Oxidizing agents such as oxygen or water vapor can be used to remove carbon contaminants from MoS2 films obtained by the MOCVD method.•The use of oxidative etching leads to both a decrease and an increase in the size of the crystal domains, depending on the deposition parameters used.•An increase in the size of domains with a decrease in the density of growth centers, provided that the oxidized states of sulfur and molybdenum atoms are effectively removed.