Ultrafast Growth of Thin Hexagonal and Pyramidal MolybdenumNitride Crystals and Films

Two-dimensional (2D) ultrathin transition-metal carbides, nitrides, and carbonitrides are considered to be a family of important functional materials for various applications; however, it is challenging to realize their fast and efficient growth from gas phase. Herein, we demonstrate a one-step direct and rapid synthesis of ultrathin molybdenum nitride (MoN) crystals with controlled thickness and morphology on liquid copper by controlling diffusion of the Mo source through a liquid copper film method. The growth of a few individual crystals with thickness down to 1 nm and continuous large-area films takes only 3 and 5 min, respectively, which is at least 20 times faster than previously reported. More importantly, a series of morphologies of MoN, including pyramidal crystals, were obtained by adjusting the synthesis time and the amount of hydrogen in nitrogen gas from 15% to 5%. The mechanism of this morphology evolution is explained through the molecular diffusion kinetic growth process. Furthermore, the ...