Nature‐Inspired Halide Perovskite Breath Figures: Unleashing Enhanced Light‐Matter Interaction

Abstract Halide perovskites offer a transformative potential for optoelectronics through tailoring the light‐matter interactions at the nanoscale. However, their susceptibility to environmental factors and limited compatibility with standard lithography techniques present significant challenges in precise nanopatterning. This work unveils a nature‐inspired breath figures (BFs) approach to pattern halide perovskites and enhancing their optoelectronic performance. The fabrication of BFs based on BiI 3 allows for changes in nanopore size (ranging from 247 to 423 nm) and their distribution. Subsequently, these BiI 3 BFs are transformed into hybrid halide MA 3 Bi 2 I 9 BFs using a vapor‐assisted technique while retaining the nanoporous topology of the BiI 3 structure. The resultant MA 3 Bi 2 I 9 BFs show significantly enhanced light absorption compared to conventional thin films, attributed to the increased extinction and lower refractive index. The optoelectronic performance of the MA 3 Bi 2 I 9 BFs is showcased by constructing a photodetector, which exhibits three orders of magnitude higher responsivity and detectivity, up to 1 AW −1 and 1.3 × 10 12 Jones, respectively, outperforming the photodetectors based on solution‐processed A 3 B 2 I 9 halide perovskite thin films. The BFs method provides flexibility in tuning nanoscale morphology, showcasing its potential in advancing lead‐free optoelectronics and paving the way for next‐generation optoelectronic devices.