Utilization of two-dimensional multicomponent Quasicrystal for NO<inf>2</inf> gas detection

The two-dimensional (2D) materials provide an effective ultra-sensitive response for sensing due to the large surface area available for the analyte. Al70Co10Fe5Ni10Cu5 (Quasicrystal-QC) alloy can be effectively exfoliated into a 2D form consisting of the decagonal quasicrystalline phase. The ultrathin thickness of a few nm (∼6 nm) was achieved, exhibiting anisotropic electron-transport properties. The 2D-QC shows pseudo-conducting behavior in the planar region, which endowed the material in nanosheets to work as ultrasensitive NO2 gas sensors (1–100 ppm) at 100 °C. The fabricated device exhibits a NO2 gas response (ΔR/Ra %) of 46% compared to its bulk counterpart. In addition, the mechanism of gas sensing was further corroborated using density functional theory (DFT) simulations and strongly support the interpretation of the experimental data.