Tellurene Nanoflake-Based Gas Sensors for the Detection of Decomposition Products of SF₆

Tellurene has a phosphorene-like puckered configuration and exhibits great air stability. This characteristic makes it highly sensitive to some gases, and therefore, it has a huge potential in gas sensing applications. In this paper, the sensing performance of tellurene-based gas sensors toward SF6 decomposition products, including H2S, SO2, SO2F2, and SOF2, was systematically investigated. Three types of tellurene-based gas sensors were fabricated: single tellurene flake with ohmic contact (RCTF sensor), single tellurene flake with nonohmic contact (DCTF sensor), and drop-cast tellurene flakes with heat function (HTF sensor). The RCTF sensor exhibited good sensitivity and selectivity toward hydrogen sulfide but slow recovery speed like most two-dimensional materials. The DCTF sensor exhibited a significant improvement in sensitivity, selectivity, and recovery speed compared with the RCTF sensor. Finally, the HTF sensor demonstrated the fastest recovery speed of all tellurene-based sensors. This work showed that the nonohmic contact and heat pulse are easy and efficient methods to enhance the performance of tellurene-based gas sensors toward hydrogen sulfide, which supports the application potential of tellurene in gas sensors.