KCS

This work presents the fabrication and characterization of NO₂ gas sensors by using ultrathin 2-D semiconductor nanoribbon (NR) membranes. The sensor employs the 8 nm-thick InAs NRs, transferred on a Si/SiO₂ substrate, as a sensing element. Using a conventional CMOS fabrication process, the sensor devices were fabricated. The sensor demonstrated the responses down to parts-per-billion (ppb) level at room temperature and the predominant reaction to NO₂ exposures. Furthermore, a 4-fold higher sensor response was observed in the 8 nm-thick InAs NR sensor compared with the one with the 18 nm-thick InAs NRs, indicating the improved size effects by scaling down to quantization limits.