The B-Site Synergistic Metal Ion Co-Doping Strategy for Enhancing the Scintillation Performance of 2D Perovskite Single Crystals

2D metal halide lead perovskite scintillators, such as phenylethylamine lead bromide (PEA₂PbBr₄), exhibit high light yields and show great potential as efficient gamma (γ) rays and fast neutron (n_f) detection materials. However, its non-significant photopeak in the γ-rays energy spectrum (resulting in poor energy resolution) and suboptimal n_f/γ discrimination ability are the most significant gaps between it and conventional scintillators. Herein, a synergistic metal ion co-doping strategy is proposed that significantly increases the exciton concentration and reduces the exciton binding energy in PEA₂PbBr₄ single crystals. This approach facilitates rapid relaxation of the crystals and reduces light loss caused by defect trapping, thereby greatly enhancing the luminescent efficiency of the crystals. The co-doping crystal PEA: 0.33CZC exhibits a significant photopeak in the ¹³⁷Cs γ-rays energy spectrum, with an energy resolution of 6.15%, which is comparable to most traditional scintillators. In addition, it demonstrates excellent n_f/γ discrimination capability in a ²⁴¹Am-Be mixed field. Using pulse shape discrimination (PSD) methods, the figure of merit (FOM) values calculated for energies around1000 and 1100 keVee are 1.22 and 1.35, respectively. These results demonstrate the great potential of co-doping PEA₂PbBr₄ scintillator for future applications in high-precision radiation detection.