Chiral perovskite-CdSe/ZnS QDs composites with high circularly polarized luminescence performance achieved through additive-solvent engineering

Chiral perovskite materials are being extensively studied as one of the most promising candidates for circularly polarized luminescence (CPL)-related applications. Balancing chirality and photoluminescence (PL) properties is of great importance for enhancing the value of the dissymmetry factor (g_lum), and a higher g_lum value indicates better CPL. Chiral perovskite/quantum dot (QD) composites emerge as an effective strategy for overcoming the dilemma that achieving strong chirality and PL in chiral perovskite while at the same time achieving high g_lum in this composite is very crucial. Here, we choose diphenyl sulfoxide (DPSO) as an additive in the precursor solution of chiral perovskite to regulate the lattice distortion. How structural variation affects the chiral optoelectronic properties of the chiral perovskite has been further investigated. We find that chiral perovskite/CdSe-ZnS QD composites with strong CPL have been achieved, and the calculated maximum |g_lum| of the composites increased over one order of magnitude after solvent-additive modulation (1.55 × 10⁻³ for R-DMF/QDs, 1.58 × 10⁻² for R-NMP-DPSO/QDs, −2.63 × 10⁻³ for S-DMF/QDs, and −2.65 × 10⁻² for S-NMP-DPSO/QDs), even at room temperature. Our findings suggest that solvent-additive modulation can effectively regulate the lattice distortion of chiral perovskite, enhancing the value of g_lum for chiral perovskite/CdSe-ZnS QD composites.