Selectively Tunable Luminescence of Perovskite Nanocrystals Embedded in Polymer Matrix Allows Direct Laser Patterning

Cesium lead halide perovskite nanocrystals (NCs) have gained enormous attention as promising light-emitting and light-converting materials. Most of their applications require embedding NCs in various matrices, which is a challenging task due to their low stability, especially in the case of red-emitting CsPbI3 NCs. In this work, a new approach is proposed allowing the formation of red-emitting perovskite NCs by anion exchange induced directly inside a solid polymer matrix using green-emitting CsPbBr3 NCs as templates and iodododecane as an iodine source. Moreover, a simple and efficient route to photo-assisted termination of the anion exchange reaction in the polymer composite after reaching desired optical properties is demonstrated. The findings allow the authors to pattern a thin composite film with an ultrashort UV laser resulting in a selective generation of green- and red-emitting features with a 15 mu m resolution.