Color‐Tunable Perovskite Nanomaterials with Intense Circularly Polarized Luminescence and Tailorable Compositions

Abstract The ability to design halide perovskite nanocrystals (PNCs) with circularly polarized luminescence (CPL) offers exceptional potential in photonic technologies. Despite recent inspiring advances, the creation of PNCs with full‐color tailorablity, outstanding CPL, and long‐term stability remains a substantial challenge. Herein, a robust strategy to craft CPL‐active PNCs is reported, exhibiting appealing full‐color tunable wavelengths, enhanced CPL, and prolonged stability. In contrast to conventional methodologies, this strategy utilizes chiral nematic mesoporous silica (CNMS) as host to render in situ confined growth of diverse achiral PNCs. By strategically engineering photonic bandgap, adjusting loading amount of PNCs, and manipulating cations/anion compositions of PNCs, robust CPL responses with tunable wavelength and intensity are successfully obtained. The resulting PNCs‐CNMS achieves stable CPL emissions with full‐color tunability and impressive luminescent dissymmetric factors up to −0.17. Remarkably, silica‐based hosts as a protective barrier confer exceptional resistance to humidity, photodegradation, and thermal stability, even up to 95 °C. Furthermore, the ability to achieve reversible CPL switching within PNCs‐CNMS is attainable by leveraging the responsiveness of CNMS matrix or dynamic behavior of impregnated PNCs. Additionally, circularly polarized light‐emitting diode devices based on PNCs‐CNMS can be conveniently fabricated. This research affords a powerful platform for designing functional chiroptical materials.