Wafer-scale MoS2 thin layers prepared by MoO3 sulfurization

TLDR

Atomically thin MoS₂ layers are prized for their direct‑gap properties and flexibility, yet scalable synthesis of large‑area films remains elusive. The study demonstrates wafer‑scale MoS₂ thin layers can be produced from MoO₃ films via a two‑step thermal process. The process involves reducing MoO₃ at 500 °C in hydrogen and sulfurizing at 1000 °C in sulfur. Characterization shows the films are polycrystalline semiconductors with uniform thickness, easily transferable to arbitrary substrates, making them suitable for flexible electronics and optoelectronics.

Abstract

Atomically thin molybdenum disulfide (MoS2) layers have attracted great interest due to their direct-gap property and potential applications in optoelectronics and energy harvesting. Meanwhile, they are extremely bendable, promising for applications in flexible electronics. However, the synthetic approach to obtain large-area MoS2 atomic thin layers is still lacking. Here we report that wafer-scale MoS2 thin layers can be obtained using MoO3 thin films as a starting material followed by a two-step thermal process, reduction of MoO3 at 500 °C in hydrogen and sulfurization at 1000 °C in the presence of sulfur. Spectroscopic, optical and electrical characterizations reveal that these films are polycrystalline and with semiconductor properties. The obtained MoS2 films are uniform in thickness and easily transferable to arbitrary substrates, which make such films suitable for flexible electronics or optoelectronics.