Growth of large-scale and thickness-modulated MoS₂ nanosheets.

Abstract

Two-dimensional MoS2 is a promising material for next-generation electronic and optoelectronic devices due to its unique electrical and optical properties including the band gap modulation with film thickness. Although MoS2 has shown excellent properties, wafer-scale production with layer control from single to few layers has yet to be demonstrated. The present study explored the large-scale and thickness-modulated growth of atomically thin MoS2 on Si/SiO2 substrates using a two-step sputtering-CVD method. Our process exhibited wafer-scale fabrication and successful thickness modulation of MoS2 layers from monolayer (0.72 nm) to multilayer (12.69 nm) with high uniformity. Electrical measurements on MoS2 field effect transistors (FETs) revealed a p-type semiconductor behavior with much higher field effect mobility and current on/off ratio as compared to previously reported CVD grown MoS2-FETs and amorphous silicon (a-Si) thin film transistors. Our results show that sputter-CVD is a viable method to synthesize large-area, high-quality, and layer-controlled MoS2 that can be adapted in conventional Si-based microfabrication technology and future flexible, high-temperature, and radiation hard electronics/optoelectronics.