Immobilized Precursor Particle Driven Growth of Centimeter-Sized MoTe Monolayer.

Molybdenum ditelluride (MoTe) 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 MoTe is challenging. Here, for the first time, we achieve the growth of a centimeter-sized monoclinic MoTe 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 MoTe monolayer, thereby realizing the inhibition of crystal growth along the [001] zone axis and the continuous growth of the MoTe monolayer. The first-principles DFT calculations prove the mechanism of immobilized precursor particles and the absorption of hydroxide ions on the MoTe monolayer. The as-grown MoTe monolayer exhibits a surface roughness of 0.19 nm and average conductivity of 1.5 × 10 S/m, which prove the smoothness and uniformity of the MoTe monolayer. Temperature-dependent electrical measurements together with the transfer characteristic curves further demonstrate the typical semimetallic properties of monoclinic MoTe. Our research elaborates the microscopic process of immobilized precursor particles to grow large-area MoTe monolayer and provides a new thinking about the growth of many other two-dimensional materials.