Scalable Synthesis of Cs2NaYCl6:Tb3+ Scintillators Toward Cutting-Edge X-Ray Radiography

Scintillators that convert high-energy X-ray photons into visible light are indispensable for a broad range of imaging applications. However, the development of high-performance scintillators combining high light yield, excellent stability, and scalable processability remains a significant challenge. Here, a simple, low-temperature, and scalable “dissolution-drying” strategy is presented for the synthesis of lead-free Cs₂NaYCl₆:Tb³⁺ double perovskite scintillators with outstanding performance. Taking advantage of the highly symmetric elpasolite structure and the efficient incorporation of Tb³⁺ions, the resulting microcrystals achieve a high light yield (≈62 359 photons MeV⁻¹), exceptional radiation resistance, an ultralow detection limit (15.19 nGy s⁻¹), and remarkable thermal stability up to 773 K. By incorporating the microcrystals into a polydimethylsiloxane (PDMS) matrix, flexible scintillator films are fabricated, demonstrating superior mechanical durability and high-resolution X-ray imaging capability (>24 lp mm⁻¹). These findings enable large-scale scintillator production and advance next-generation X-ray radiography, offering high sensitivity, stability, flexibility, and versatility for advanced radiographic systems and future optoelectronic applications.