Ultrahigh‐resolution (λ/10) Femtosecond Laser Writing of Polymer‐Encapsulated Multicolor Perovskite Patterns Beyond the Diffraction Limit

Abstract Laser direct writing enables precise tailoring and patterning of semiconductor materials at the micro‐and nanoscale, which is crucial for optoelectronic devices. However, the resolution of laser writing is limited by the diameter of the Airy disk. Herein, a femtosecond (fs) laser super‐resolution writing (FsLSRW) technique is demonstrated for subwavelength patterning of stable perovskite nanostructures, achieving feature sizes as small as λ/10, with the line width reaching 80 nm. By leveraging the fs‐laser's flexible, precise, and non‐thermal diffused patterning capabilities, multicolor perovskite patterns are successfully produced with arbitrary design and pixel arrays. The multicolor perovskite patterns exhibit high hydrolytic, oxidative, and thermal stability due to their encapsulation in a polymer matrix. Furthermore, through precise adjustment of the laser focus plane, the writing of different information is demonstrated on two distinct spatial planes within a double‐layer stacked perovskite composite film, enabling the production of dynamic 3D codes at the micro‐ and nanoscale. The high‐efficiency and precision of FsLSRW technology pave a novel path for perovskite devices in fields such as information security, data storage, and optical encryption.