Optimizing Conditions For Growth of Transition Metal Dichalcogenides Using Chemical Vapor Deposition

Two-dimensional materials are receiving growing attention due to their physical properties that often differ from their bulk counterparts. 2D niobium diselenide (NbSe₂), a metallic compound, and 2D molybdenum disulfide (MoS₂), a semiconductor, both have great potential for integration into novel 2D structures and devices. So far, few layers of NbSe2 has been synthesized using non-chemical vapor deposition (CVD), methods to study their physical properties. MoS₂ has been synthesized using CVD but not continuous monolayers using water-assisted CVD approach. The purpose of this work is to determine optimal conditions to grow niobium diselenide continuous layers and molybdenum diselenide continuous layers by CVD. With this aim, we varied the amount of precursors, the growth time, the growth temperature, and the carrier gas. Powder niobium (IV) chloride and selenium were used as solid precursors for evaporation for niobium diselenide growth. Powder molybdenum disulfide and powder sulfur were used as solid precursors for molybdenum disulfide growth. For both, SiO2 substrates were pleased downstream at different positions in the furnace. The samples were characterized by using Raman spectroscopy, SEM, and AFM.