Nanometer-thick transition-metal dichalcogenides (TMDs) have attracted increasing research interest because of their exotic physical properties, but their high-yield and large-scale synthesis remains a challenge for their practical device applications. In this study, we realize the high-yield synthesis of nanometer-thick single-crystalline Mo(Te1-xSx)2 plates by a facile chemical vapor deposition method. Adding S powders in the precursors can result in the products varying from well-faceted MoTe2 hexagonal plates to irregular Mo(Te1-xSx)2 plates with randomly stacked nanometer-thick layer steps. Moreover, their lateral dimension increases from several μm for binary MoTe2 to several tens of μm for ternary Mo(Te1-xSx)2. More interestingly, such irregular Mo(Te1-xSx)2 plates can form few layers by ultrasonic exfoliation. Our detailed electron microscopy analyses show that three kinds of S forms influence the ternary growth. In particular, elemental S8 intercalations play an important role in the growth and exfoliation of ultrathin Mo(Te1-xSx)2 plates. This study enriches the fundamental understanding of zero-valent intercalation in TMDs and provides a new insight into secure high-yield nanometer-thick TMDs, which is critical for practical applications.
Keywords: 2D materials; CVD growth; electron microscopy; few-layer MoTe2; intercalation.