Simulation and design of light extraction efficiency in (PEA)₂PbBr₄ perovskites enhanced by 2D and 3D photonic crystals

Novel perovskite scintillators have attracted widespread attention because of their excellent scintillation properties. This study uses the emerging perovskite scintillator (PEA)₂PbBr₄ as an example, which achieves a light yield of up to 43,623 photons/MeV under X-ray excitation. However, this value is still significantly lower than the theoretical light yield of 95,000 photons/MeV. To further enhance its light output, this study systematically analyzed the impact of two-dimensional, three-dimensional, and three-dimensional gradient photonic crystal structures on the light extraction efficiency of (PEA)₂PbBr₄ using Rsoft and Lighttools software. The results show that depositing a conformal layer on a two-dimensional photonic crystal scintillator with a diameter of 500 nm enhanced light extraction efficiency by 68%. Similarly, for a scintillator containing only a three-dimensional photonic crystal, when the refractive indices of the A and B layers are 1.59 and 2.7, respectively, and both layers consist of nanospheres with a diameter of 300 nm, the addition of a conformal layer improved light extraction efficiency by 41%. Furthermore, we found that by adjusting the diameter and refractive index of the micro-spheres in the three-dimensional photonic crystal, precise control of the light emission direction within a range of 0° to 40° can be achieved. In addition, we introduced a sixth-order polynomial fitting method to process light-intensity data. This approach enhances calculation accuracy compared to the traditional single-angle light intensity calculation method.