High-performance gas sensors based on a thiocyanate ion-doped organometal halide perovskite

Thin films of a thiocyanate ion (SCN-)-doped organometal halide perovskite, CH3NH3PbI3-x(SCN)(x), were used as a sensing material for developing high-performance gas sensors. The CH3NH3PbI3-x(SCN)(x)-based chemiresistor-type sensor can sensitively and selectively detect acetone and nitrogen dioxide (NO2) at room temperature with high sensitivities of 5.6 x 10(-3) and 5.3 x 10(-1) ppm(-1). The limits of detection for acetone and NO2 were measured to be 20 ppm and 200 ppb. This sensor also exhibited excellent repeatability, and its environmental stability was greatly improved by doping the perovskite with SCN ions.