Halide perovskite (ABX3) have demonstrated great advantages over conventional semiconductors for the next-generation photoelectronic devices due to their outstanding photophysical properties, such as tunable band gaps, long carrier diffusion length, long carrier lifetime, and high quantum efficiency. In addition, it is also very suitable for humidity sensing because of its environmental sensitivity. However, halogen elements have a great impact on the photophysical properties of perovskite because of their different exchange properties with the environment and mobility. In this work, the samples with three different anions of CsPbCl3, CsPbBr3, and CsPb(Br0.5Cl0.5)3 were used, and humidity sensing and stability experiments were carried out in a humidity environment at a relative humidity (RH) of 30%-90%. It is found that the single-anion halide perovskite materials possess low sensitive at low humidity and possess poor stability at high humidity. While the mixed-halide perovskite CsPb(Br0.5Cl0.5)3 demonstrated better sensitivity and reversible in the range of 30%-90% RH. It shows that this is related to the shallow-level defect types of different halide anions, which lead to different phenomena. The ability of different materials to bind water molecules is also an important reason. Therefore, it indicates that the anion-mixed halide perovskite humidity sensor can be used in future environmental detection applications has great potential.
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