2D Perovskite Mn²⁺‐Doped Cs₂CdBr₂Cl₂ Scintillator for Low‐Dose High‐Resolution X‐ray Imaging

Abstract High‐performance X‐ray scintillators with low detection limits and high light yield are of great importance and are a challenge for low‐dose X‐ray imaging in medical diagnosis and industrial detection. In this work, the synthesis of a new 2D perovskite, Cs₂CdBr₂Cl₂, via hydrothermal reaction is reported. By doping Mn²⁺ into the perovskite, a yellow emission located at 593 nm is obtained, and the photoluminescence quantum yield (PLQY) of Cs₂CdBr₂Cl₂:5%Mn²⁺ perovskite reaches the highest value of 98.52%. The near‐unity PLQY and negligible self‐absorption of Cs₂CdBr₂Cl₂:5%Mn²⁺ enable excellent X‐ray scintillation performance with a high light yield of 64 950 photons MeV⁻¹ and low detection limit of 17.82 nGy_air s⁻¹. Moreover, combining Cs₂CdBr₂Cl₂:5%Mn²⁺ with poly(dimethylsiloxane) to fabricate a flexible scintillator screen achieves low‐dose X‐ray imaging with a high resolution of 12.3 line pairs (lp) mm⁻¹. The results suggest that Cs₂CdBr₂Cl₂:5%Mn²⁺ is a promising candidate for low‐dose and high‐resolution X‐ray imaging. The study presents a new approach to designing high‐performance scintillators through metal‐ion doping.