Circularly polarized luminescence enlargement from crystals to oriented films of enantiopure 2D hybrid perovskites

Chiral 2D organic-inorganic hybrid perovskites (C-2D-OIHPs) with circularly polarized luminescence (CPL) have important promising applications in optical, electronic, and chiroptoelectronic devices. Herein, we report enantiomeric crystals of R/S-FMBA)₂PbBr₄. (FMBA = 4-fluorophenethylamine), which demonstrated bright room-temperature CPL emission. For the first time, the oriented films along the c-axis of this pair of C-2D-OIHPs exhibited a 16-fold increase in the asymmetry factors of absorbance (g_CD) and a 5-fold rise in the asymmetry factors of CPL (g_lum), reaching up to ± 1 × 10^-2.