In-situ growth of perovskite nanocrystals for high-contrast defects active imaging on components.

Discontinuities in heat conduction induced by micro-nano defects can lead to localized heat concentration, thereby altering the surface temperature distribution of components. These localized thermal variations significantly influence the nucleation and in-situ growth kinetics of perovskite nanocrystals (NCs), which tend to preferentially form and selectively grow within the defective regions. Based on this phenomenon, we propose a microscopic imaging strategy for defects by leveraging the in-situ growth of CsPbBr3 NCs, enabling direct translation of defect-induced thermal information into visually intuitive fluorescence signals. Through monovalent alkali metal cation doping, the fluorescence intensity of NCs is enhanced by 12.8 times. By integrating a LAB-HSV color-space fusion algorithm, we constructed a micro-nano defect detection system based on the in-situ grown NCs. The system achieves a maximum enhancement of 356% in fluorescence image contrast and an 862% increase in edge strength. This system allows for the visualization of both surface and subsurface defects on planes and curved surfaces. The minimum resolvable feature size is 400 nm, and the maximum field of view is 1.76 mm2. Furthermore, subsurface defects at depths up to 1 mm can be effectively detected.