Layer-controlled continuous MoS growth using a spin-coatable metal precursor buffer.

Continuous large-area MoS growth holds significant potential for next-generation optoelectronic applications, yet achieving it efficiently and reproducibly with the conventional chemical vapor deposition (CVD) process remains a challenge due to inconsistent precursor adsorption and non-uniform nucleation. In this study, we developed a pH-optimized metal precursor buffer that enables uniform spin-coating and facilitates continuous MoS growth. Sodium cholate (SC) acts as both a dispersant and a buffer, transforming molybdenum oxide into a dispersion-stable sodium molybdate (NaMoO)/SC complex. This complex forms a stable, uniformly spin-coatable dispersion at pH = 5.3, allowing it to form hydrogen bonds with the SiO/Si substrate. Additionally, increasing the complex concentration enhances precursor adsorption, enabling controlled MoS layer formation CVD. Using this approach, we successfully fabricated continuous, centimeter-scale MoS films in varying layer numbers. Real-time observation reveals the growth kinetics of the continuous MoS film in terms of contrast value, according to the reaction time and temperature, indicating that the growth can occur at temperatures as low as 500 °C. This stable, scalable, and reproducible spin-coating technique, utilizing a metal precursor buffer, offers a robust pathway for producing large-area transition metal chalcogenide structures, advancing the development of 2D material-based applications.