Controllable Growth Of Two-Dimensional Niobium Disulfide And Tantalum-Doped Niobium Disulfide

Two-dimensional transition metal dichalcogenides are one of the focuses in condensed matter physics for its intriguing properties.In consideration of the prospects of Nb S₂in the design and development of new electronic prototype devices,a method to realize the controllable growth of large-scale two-dimensional Nb S₂and its alloy is in an urgent need so that the property modulation research and application of new electronic prototype device in base of Nb S₂and its alloy can be promoted.Here,by utilizing the atmospheric chemical vapor deposition,we successfully realize the controllable growth of Nb S₂thin films.The growth takes transition metal oxide and sulfur as precursors,adapts the flux NH₄Cl,uses mica as growing substrates,keeps nitrogen and hydrogen as carrier gases with a hydrogen concentration of 5%and keeps growing at 800℃for 20 minutes.The acheived largest size of the Nb S₂thin films is about 115μm.The growth of large-area two-dimensional tantulum-doped Nb S₂can be realized by the same method with a lower temperature of 750℃.The acheived largest size of the tantulum-doped Nb S₂thin films is about 112μm.The effection of the growth temperature,carrier gas flow rate and the distance between mica and sulfur on the growth is studied and corresponding probable reasons from growth process is proposed.The as-grown thin films are 3R phase with high-quality single crystalline through the Raman spectrum and electron microscopy characterizations.Our findings will advance the controllable growth of large-scale two-dimensional transition metal dichalcogenides via chemical vapor deposition and provide possibilities for two-dimensional material device development.