Sensitive NO detection by lead-free halide Cs2TeI6 perovskite with Te-N bonding

Halide perovskites are one of the most promising materials for gas detection, with applications ranging from gas quality monitoring to explosive detection and medical diagnostics. However, the use of halide perovskites to achieve trace detection of nitric oxide (NO) is almost a blank in gas sensing field. Herein, we report that Cs2TeI6 with Te-N bonding realizes outstanding sensing performance for NO. Fern-like Cs2TeI6 are synthesized by specifically, it has the lowest detection limit of 60 ppb, extremely 98% batch stability and high NO selectivity. Further theoretical calculation reveals that the Te 5pz and N 2pz have substantial bonding interactions due to the formation of strong σ bond, which is the root cause of the change in conductivity of the sensor. This work highlights the Te-N orbital coordination to detect trace NO as low as 60 ppb.