Lead-free metal-halide hybrid x-ray detectors are fundamentally limited by strong exciton localization and inefficient carrier transport, preventing their deployment in high-sensitivity flexible imaging systems. Here we establish a chirality-modulated spin-engineering strategy that intrinsically overcomes these limitations by quantitatively linking molecular chirality, Rashba spin splitting, carrier transport, and detector performance in a chiral Bi/Sb metal-halide hybrid series, (S1−rRr-CHEA)4(Bi0.5Sb0.5)2I10 (CHEA = 1-cyclohexylethylamine), where the enantiomeric ratio functions as a continuous structural control parameter. Homochiral assemblies maximize inversion-symmetry breaking, producing a giant Rashba coefficient up to 0.41 eV Å−1 and enabling long-lived (> 1 ns) spin polarization that suppresses excitonic localization. As a result, the exciton binding energy decreases by 42% while the carrier mobility–lifetime product (μτ) increases fourfold, establishing an intrinsic spin-modulated transport mechanism in lead-free metal-halide hybrids. Flexible detectors fabricated from the optimized homochiral composition exhibit deformation-invariant x-ray imaging with a record sensitivity of 8002 µC Gy−1 cm−2, an ultralow detection limit of 75 nGy s−1, and exceptional robust endurance under couples of stresses including thermal, humidity, mechanical, and irradiation. This work identifies molecular chirality as a programmable handle to control spin–orbit interactions and carrier dynamics, providing a general materials-level strategy for high-performance, environmentally benign radiation detectors and spin-enabled optoelectronics.
原文链接：http://onlinelibrary.wiley.com/doi/10.1002/anie.4040066
