Flexible chemical sensors based on hybrid layer consisting of molybdenum disulphide nanosheets and carbon nanotubes

A facile synthesis method was developed for preparing hybrid 2-dimensional (2D) films, based on large-scale molybdenum disulfide (MoS2) nanosheets and single-walled carbon nanotubes (SWCNTs), for flexible sensors. Here, 1-dimensional (1D) SWCNTs were combined with MoS2 nanosheets during the MoS2 synthesis process for improving the flexibility and stability of the 2D MoS2 nanosheet. Uniform MoS2 nanosheets were successfully synthesized via chemical vapor deposition (CVD) using a porphyrin-type organic promoter. This study demonstrates the high performance and enhanced sensitivity of the chemical gas sensors that were fabricated using hybrid MoS2-SWCNT layers; the enhancement is due to the sensitive gas adsorption by SWCNTs in the MoS2 nanosheets. In addition, the hybrid MoS2-SWCNT films, transferred on a flexible polyethylene terephthalate (PET) substrate, were employed for the analysis of physical properties of chemical sensors as a function of the number of bending cycles. The hybrid MoS2-SWCNT-based sensors showed stable sensing performance after 105 bending cycles, whereas the resistance of MoS2-based sensors increased to approximately 300% under the same bending process.