Chiral Emission from Twisted Moiré Metasurfaces with Emissive Gap Layer

ABSTRACT Compact chiral meta‐devices capable of directly emitting circularly polarized light are increasingly in demand in applications such as sensing, imaging, and information processing. However, practical application of emissive chiral metasurfaces with complex meta‐atoms is currently hindered by their reliance on costly and time‐consuming fabrication techniques, such as electron‐beam lithography. Recently, twisted moiré chiral metasurfaces have attracted significant attention for their unique electromagnetic responses, achieving intrinsic chirality through lattice twists rather than intricate designs. Nonetheless, the emission properties of these lattice‐twisted moiré chiral metasurfaces remain to be investigated. In this paper, an efficient and cost‐effective fabrication method is presented for the first time, enabling the creation of large‐area twisted moiré chiral metasurfaces that incorporate reusable structural layers and an emissive gap made from materials including dyes, quantum dots, and halide perovskite. A remarkably high luminescence dissymmetry factor of −1.21 is achieved. Furthermore, their exceptional capabilities in tuning emission chirality are experimentally demonstrated. Reciprocity‐based simulations reveal a strong correlation between the emission chirality and the asymmetry of field enhancements. This work paves the way for the development of large‐area, cost‐effective chiral light sources with exceptional tunability.