Improving the Scintillation Performance of PEA₂PbBr₄ Through Zn²⁺ and Sb³⁺ Interstitial Doping Strategy

Organic-inorganic halide 2D perovskite single crystals have recently emerged as promising scintillators for gamma (γ) rays and fast neutrons (n_f) detection. However, their energy resolution in γ-rays detection still significantly lags behind that of perovskite semiconductor detectors. Improving crystal defects and enhancing light yield to optimize light output detected by the photomultiplier tube are crucial strategies for addressing this issue. Herein, it is demonstrated that Zn²⁺ and Sb³⁺ cation interstitial doping strategy can effectively reduce internal defects within the phenylethylammonium lead bromide (PEA₂PbBr₄) crystal by regulating lattice expansion. This approach also suppresses light loss caused by exciton-exciton annihilation and accelerates electron-hole recombination processes, optimizing both the luminescence intensity and decay lifetime of the scintillator. The Zn²⁺ and Sb³⁺ doping PEA₂PbBr₄ scintillator achieve an optimal energy resolution of 4.84% and 5.65% at 662 keV for the photopeak, respectively. Additionally, in the ²⁴¹Am-Be field, effective identification of n_f and γ-rays around 1100 keVee is achieved using a pulse shape discrimination (PSD) method, with the figure of merit (FOM) being 0.85 and 1.03, respectively. This work provides a reliable new approach for optimizing the scintillation performance of 2D perovskite and promotes the application of 2D perovskite scintillator in γ-rays and n_f detection.