Ammonium Salts: New Synergistic Additive for Chemical Vapor Deposition Growth of MoS.

Controllable and scalable fabrication is the precondition for realizing the large number of superior electronic and catalytic applications of MoS. Here, we report a new type of synergistic additives, ammonium salts, for chemical vapor deposition (CVD) growth of MoS. On the basis of the catalysis of ammonium salts, we can achieve layer and shape-controlled MoS domains and centimeter-scale MoS 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, MoS 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 MoS 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 MoS toward real applications in modern electronics and catalysis.