Poisoning of MoO$_{3}$ Precursor on Monolayer MoS$_{2}$ Nanosheets Growth by Tellurium-Assisted Chemical Vapor Deposition
Zhi-Gang Wang, Fei Pang**
Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872
Abstract：We obtain molybdenum disulfide (MoS$_{2}$) nanosheets (NSs) with edge sizes of 18 μm by direct sulfuration of MoO$_{3}$ powder spread on the SiO$_{2}$/Si substrates. However, the undesirable MoO$_{3}$ nanoparticles (NPs) left on the surface of MoS$_{2}$ NSs poison the MoO$_{3 }$ precursor. Introducing Te vapors to react with MoS$_{2}$ to form low melting point intermediate MoS$_{x}$Te$_{2-x}$, the evaporations of MoO$_{3}$ precursor recover and MoO$_{3}$ NPs disappear. Thus Te vapor is effective to suppress poisoning of the MoO$_{3}$ precursor. Selecting the appropriate amount of Te vapor, we fabricate monolayer MoS$_{2}$ NSs up to 70 μm in edge length. This finding can be significant to understand the role of Te in the Te-assisted chemical vapor deposition growth process of layered chalcogenide materials.
2017, Vol. 34 
