Ultra Stable X-Ray Imaging Through a Mutually Reinforcing Strategy Between Perovskite Nanocrystal-Polymethyltrifluoropropylsiloxane

Abstract

The instability of halide perovskite nanocrystals (PNCs) and related composite polymer films posed considerable challenges for application in flexible optoelectronic devices. Herein, perovskite nanocrystal-polymethyltrifluoropropylsiloxane (PNCs-PMFS) composites are developed that exhibit outstanding optical stability and irradiation resistance through a mutually reinforcing strategy. The photoluminescence (PL) intensity of PNCs-PMFS remained stable after four heating cycles, whereas perovskite nanocrystal-polydimethylsiloxane (PNCs-PDMS) composites exhibited a 31% decrease in PL intensity. Moreover, PNCs-PMFS demonstrated superior luminescence stability under UV and X-ray irradiation due to strong ion-dipole interactions between PNCs and trifluoromethyl (CF₃) dipoles. Under γ-ray irradiation (300 kGy), PNCs-PMFS retained 73% (2.86 MPa) of the initial mechanical strength, while PMFS without PNCs retained only 51%. This enhancement is attributed to the effective reduction of free radical concentration in the system by PNCs, as confirmed by electron spin resonance (ESR) and curing curve. Density-functional theory (DFT) calculations further indicated that PNCs adsorbed free radicals, thereby facilitating interfacial charge transfer and forming a stable resonance structure. These advancements enabled PNCs-PMFS to serve as scintillation screens for X-ray detection and imaging, achieving a spatial resolution of 19.0 lp mm⁻¹ and a detection limit of 3.78 µGy s⁻¹, offering novel insights for designing of X-ray detectors in high-energy radiation environments.