Microfibers Doped with Perovskite Nanocrystals for Ultralow-Loss Waveguides

Low-loss optical waveguides have attracted intense interests as the building blocks for photonic devices and integrated circuits. Herein, we employed the all-inorganic halide perovskite nanocrystal (IHPNs)-doped polymer microfibers for developing the active waveguides for the first time. We reveal that the absorption coefficient (2.6 cm–1) of the CsPbBr3 IHPNs-doped polymer fibers is 1 order of magnitude lower than that of traditional CdSe quantum dots (QDs)-based microfibers, which can be attributed to the much higher photoluminescence quantum yield of IHPNs. Moreover, manganese ions (Mn2+) were successfully inserted into CsPbX3 IHPNs to engineer the Stokes shift and eliminate the reabsorption effect. As a result, the Mn:CsPb­(Br/Cl)3IHPNs-doped polymer microfibers exhibited a record-low absorption coefficient of 0.33 cm–1. These findings reveal a great potential of perovskite nanocrystals in photonic technologies that also paves the way for solution-processed QDs in low-loss and long-range optical guiding.