RESUMO
Controllable and scalable fabrication is the precondition for realizing the large number of superior electronic and catalytic applications of MoS2. Here, we report a new type of synergistic additives, ammonium salts, for chemical vapor deposition (CVD) growth of MoS2. On the basis of the catalysis of ammonium salts, we can achieve layer and shape-controlled MoS2 domains and centimeter-scale MoS2 films. Compared to frequently used alkali metal ions as the catalysts, ammonium salts are decomposed completely at low temperature (below 513 °C), resulting in clean and nondestructive as-grown substrates. Thus, MoS2 electronic devices can be directly fabricated on them, and the redundant transfer step is no longer needed. This method can also promote the direct growth of MoS2 on the conductive substrate and boost the improvement of hydrogen evolution reaction (HER) performance. The ammonium salt-mediated CVD method will pave a new way for MoS2 toward real applications in modern electronics and catalysis.
RESUMO
Because of its unique electronic band structure, molybdenum disulfide (MoS2) has been regarded as a star semiconducting material. However, direct growth of continuous and high-quality MoS2 films on SiO2/Si substrates is still very challenging. Here, we report a facile chemical vapor deposition (CVD) method based on synergistic modulation of precursor and Na2SO4 catalysis, realizing the centimeter scale growth of a continuous MoS2 film on SiO2/Si substrates. The as-grown MoS2 film had an excellent spatial homogeneity and crystal quality, with an edge length of the composite domain as large as 632 µm. Both experimental and theoretical results proved that Na tended to bond with SiO2 substrates rather than to interfere with as-grown MoS2. Thus, they showed decent and uniform electrical performance, with electron mobilities as high as 5.9 cm2 V-1 s-1. We believe our method will pave a new way for MoS2 toward real application in modern electronics.