1D Cs2AgBr3:Mn2+ crystals to realize high-resolution X-ray scintillation imaging†

Abstract

Lead halide perovskites have been intensively explored as scintillators owing to their cost-effective fabrication and high radioluminescence. The intrinsic unstable characteristics and nocuous Pb elements in CsPbX₃-related scintillators pose serious challenges to their commercial applications. Herein, lead-free and highly radioluminescent Cs₂AgBr₃:Mn²⁺ scintillators are reported for high-resolution X-ray imaging. The incorporation of Mn²⁺ ions enables the originally nearly nonluminescent Cs₂AgBr₃ crystals to display a highly photoluminescent green emission centered at ∼519 nm, with a photoluminescence light yield (PLQY) of 88.7%. Detailed spectral characterizations were implemented to reveal the effects of Mn²⁺ dopants on the photoluminescence (PL) behaviour of the Cs₂AgBr₃ crystals. The radioluminescent measurement revealed that the CsAg₂Br₃:Mn²⁺ crystals achieved a detection limit of 478.8 nGy_air s⁻¹. The as-fabricated Cs₂AgBr₃:Mn²⁺@PMMA composite film exhibits excellent X-ray imaging performance with a resolution of 24 lp mm⁻¹. This eco-friendly lead-free halide crystal is considered the most potential candidate for next-generation scintillators.