Coordination-Constraint-Driven Enhanced Chirality Induction in Perovskite Quantum Dot Solids

Perovskite quantum dots (PQDs) are promising chiroptical materials owing to their soft ionic lattice and strong surface-lattice coupling. However, achieving efficient chirality induction in solid-state chiral PQD (CPQD) thin films remains a fundamental challenge. Here, we establish sterically constrained surface coordination as a strategy to promote chirality induction and lattice asymmetry in PQD solids. Using a synthesis-on-substrate approach, CsPbBr₃ CPQD thin films with exclusive chiral ligand coverage are directly constructed, enabling well-defined ligand-surface interactions. Density functional theory calculations indicate that ligand coordination geometry, rather than ligand density, governs the strength of asymmetric interaction at the PQD surface. As a result, the CPQD films exhibit photoluminescence dissymmetry factors exceeding 10^–2 across the tunable range of 468–515 nm, reaching 3.47 × 10^–2 at 510 nm, and combine pronounced chirality-induced spin selectivity with high electrical conductivity. Spin light-emitting diodes based on the CPQD films achieve an electroluminescence dissymmetry factor of 0.15 and an external quantum efficiency of 17.9%. Our results highlight the role of coordination environment in chirality transfer and underscore the potential of CPQDs for spin-optoelectronic applications.