Quasi-2D Chiral Perovskite Janus-Structural Nanofiber Film With Tunable Spectrum and Energy-Transfer-Amplified...

Chiral metal halide perovskites hold great potential as circularly polarized luminescent (CPL) materials owing to their exceptional optoelectronic properties. However, chirality-induced lattice distortions in intrinsically chiral systems often reduce photoluminescence (PL) efficiency, making it challenging to balance chirality and emission performance. In this study, we present a general strategy enabling efficient energy transfer (ET) from chiral quasi-two-dimensional (quasi-2D) perovskite nanosheets to achiral perovskite nanocrystals or dye molecules, achieving extended fluorescence lifetimes and enhanced CPL activity in achiral hosts. We establish a direct correlation between ET efficiency and chiral amplification in quasi-2D chiral perovskite/achiral perovskite composites. The Janus-type heterostructures exhibit remarkable ET efficiency and pronounced chiral amplification, leading to a fourfold increase in the photoluminescence quantum yield of achiral components and a luminescence dissymmetry factor (g_lum) value of 4.32 × 10^-3, representing a 50% enhancement compared to pristine chiral perovskites. This design can be extended to achieve full-spectrum, white-light CPL emission. The optimized Janus composites show excellent environmental stability, highlighting their practical applicability. Overall, this work establishes a versatile platform for developing high-efficiency, spectrally tunable, and integrated CPL light sources, providing new opportunities for advanced chiroptoelectronic applications.