Directional and Fast Photoluminescence from CsPbI3 Nanocrystals Coupled to Dielectric Circular Bragg Gratings

Lead halide perovskite nanocrystals (NCs), especially the all-inorganic perovskite NCs, have drawn substantial attention for both fundamental research and device applications in recent years due to their unique optoelectronic properties. To build high-performance nanophotonic devices based on perovskite NCs, it is highly desirable to couple the NCs to photonic nanostructures for enhancing the radiative emission rate and improving the emission directionality of the NCs. In this work, we synthesized high-quality CsPbI3 NCs and further coupled them to dielectric circular Bragg gratings (CBGs). The efficient couplings between the perovskite NCs and the CBGs resulted in a 45.9-fold enhancement of the photoluminescence (PL) intensity and 3.2-fold acceleration of the radiative emission rate. Our work serves as an important step for building high-performance nanophotonic light emitting devices by integrating perovskite NCs with photonic nanostructures.