Immobilized Precursor Particle Driven Growth of Centimeter-Sized MoTe₂ Monolayer

Molybdenum ditelluride (MoTe₂) has attracted ever-growing attention in recent years due to its novel characteristics in spintronics and phase-engineering, and an efficient and convenient method to achieve large-area high-quality film is an essential step toward electronic applications. However, the growth of large-area monolayer MoTe₂ is challenging. Here, for the first time, we achieve the growth of a centimeter-sized monoclinic MoTe₂ monolayer and manifest the mechanism of immobilized precursor particle driven growth. Microscopic characterizations reveal an obvious trend of immobilized precursor particles being consumed by the monolayer and continuing to provide a source for the growth of the monolayer. Time-of-flight secondary ion mass spectrometry verifies the attachment of hydroxide ions on the surface of the MoTe₂ monolayer, thereby realizing the inhibition of crystal growth along the [001] zone axis and the continuous growth of the MoTe₂ monolayer. The first-principles DFT calculations prove the mechanism of immobilized precursor particles and the absorption of hydroxide ions on the MoTe₂ monolayer. The as-grown MoTe₂ monolayer exhibits a surface roughness of 0.19 nm and average conductivity of 1.5 × 10^-5 S/m, which prove the smoothness and uniformity of the MoTe₂ monolayer. Temperature-dependent electrical measurements together with the transfer characteristic curves further demonstrate the typical semimetallic properties of monoclinic MoTe₂. Our research elaborates the microscopic process of immobilized precursor particles to grow large-area MoTe₂ monolayer and provides a new thinking about the growth of many other two-dimensional materials.