Synthesis of single-crystalline molybdenum disulfide on molybdenum films aided with NaCl solution treatment

Abstract

Two-dimensional MoS2 exhibits excellent optical and electrical properties, which have aroused great research interest in a wide range of interdisciplinary fields. Chemical vapor deposition (CVD) is considered to be an effective and simple technique for the synthesis of monolayer MoS2 thin films. However, the controlled growth of large size single-crystalline monolayer MoS2 is still a challenge. This work presents controlled growth of large-area monolayer MoS2 using evaporated Mo films pretreated with NaCl solution. The maximum size of the monolayer MoS2 flake can reach 300 μm, which could be obtained by optimizing the mass concentration of NaCl solution. In addition, the study also reveals that an appropriate increase of NaCl concentration can affect the edge growth rate of sulfur and molybdenum, thus affecting the relative stability of the growth mode of the crystal. This provides new insight and research direction for the specific mechanism of fractal growth, which can also be used for the controllable growth of MoS2 with high-density Mo-terminated edges for catalytic applications.

Keywords

• Monolayer MoS2
• Chemical vapor deposition
• Mo films
• NaCl solution
• Fractal growth