Preparation of humidity sensors based on CsPbBr₃ quantum dots for applications in microcrack detection

Perovskite CsPbBr3-Fe quantum dots ( QDs) with good dispersion and uniform size were prepared using a simple solution route combined with an acetylacetone iron (AAI) modification technology. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. Then, a resistive humidity sensor was fabricated with the perovskite CsPbBr3-Fe QDs by a spin-coating method. The humidity sensitivity measurement results showed that the device had good linear and rapid response characteristics with a detection range of 10% to 100% relative humidity (RH). At 70% RH, the humid sensor displayed a sensitivity of 1.1, a response time of 38 s, and a recovery time of 38 s, respectively. In addition, we used the finite element method (FEM) to simulate the leakage behavior of pipeline microcracks, and verified the feasibility of using humidity sensors to detect the leakage locations by simulating the distribution of flow velocity and pressure fields under different flow velocities and pressures.