Low-temperature synthesis of 2D MoS on a plastic substrate for a flexible gas sensor

The efficient synthesis of two-dimensional molybdenum disulfide (2D MoS 2 ) at low temperatures is essential for use in flexible devices. In this study, 2D MoS 2 was grown directly at a low temperature of 200 °C on both hard (SiO 2 ) and soft substrates (polyimide (PI)) using chemical vapor deposition (CVD) with Mo(CO) 6 and H 2 S. We investigated the effect of the growth temperature and Mo concentration on the layered growth by Raman spectroscopy and microscopy. 2D MoS 2 was grown by using low Mo concentration at a low temperature. Through optical microscopy, Raman spectroscopy, X-ray photoemission spectroscopy, photoluminescence, and transmission electron microscopy measurements, MoS 2 produced by low-temperature CVD was determined to possess a layered structure with good uniformity, stoichiometry, and a controllable number of layers. Furthermore, we demonstrated the realization of a 2D MoS 2 -based flexible gas sensor on a PI substrate without any transfer processes, with competitive sensor performance and mechanical durability at room temperature. This fabrication process has potential for burgeoning flexible and wearable nanotechnology applications. The efficient synthesis of two-dimensional molybdenum disulfide (2D MoS 2 ) at low temperatures is essential for use in flexible devices.