A high-performance impedimetric humidity sensor based on lead-free halide perovskite Cs2TeCl6

Lead halide perovskites have attracted extensive attention in lately because of the high cost-effectiveness, simple manufacturing process and adjustable properties. However, lead halide perovskites are rarely used in humidity sensors due to the toxicity and instability. In this work, we synthesized an all-inorganic lead-free halide perovskite Cs2TeCl6 for humidity detection. The Cs2TeCl6 sensor represents high humidity sensing performance in an impedimetric mode, especially ultra-high response value (1.59 × 106) and fast response time (1 s). Moreover, the Cs2TeCl6 sensor also displays good reliability and long-term stability in the operating range of relative humidity (RH) from 11% to 97%. In addition, the humidity sensing mechanism was discussed by impedance analysis. This work provides a feasible guidance for lead-free halide perovskites in electronical sensory devices.