Enhancing X-ray Sensitivity via the Antenna Effect in Quantum Shells with Multiexciton Emission

Quantum shells (QSs) with efficient multiexciton emission can generate multiple excitons per particle under high-energy excitation, thereby improving exciton utilization under intense X-ray exposure and offering strong potential for X-ray-based scintillation applications. However, these QSs are typically composed of low-atomic-number (<i>Z</i>) elements, which substantially limits their X-ray absorption efficiency and leads to poor X-ray sensitivity. Here, we overcome this fundamental limitation by introducing a high-<i>Z</i> antenna-sensitization strategy that couples QSs to heavy-element molecular absorbers, which act as X-ray harvesting centers and funnel energy into the QSs via efficient interfacial transfer. By combining enhanced X-ray absorption with efficient interfacial energy transfer and improved exciton utilization, we achieve more than an order-of-magnitude increase in multiexciton-driven QS radioluminescence (RL) relative to pristine shells. Additionally, a high X-ray imaging resolution of 25.2 lp mm^-1 was achieved, exceeding the performance of most previously reported X-ray imaging scintillators. These findings offer a promising design strategy for advancing QS-based materials toward high-performance X-ray imaging applications.