Surface nanostructures for enhancing the light extraction efficiency of CsPbBr₃ crystals

By introducing periodic nanocones and nanohole structures on the surface of CsPbBr₃ scintillators, the study explores how these two types of nanostructures affect the transmittance of CsPbBr₃ crystals. The analysis investigates the impact of structural parameters such as periodicity, radius, and height on transmittance. Through simulations and optimization using FDTD software, it was found that both nanocones and nanoholes on the surface of CsPbBr₃ crystals significantly enhance light transmittance, thereby improving the scintillator light extraction efficiency. For a dipole light source at 527 nm, the nanocone model achieves a maximum transmittance improvement of 16.04 times, while the nanohole model increases transmittance by up to 87%. At 550 nm, the nanocone model achieves an even greater transmittance improvement of 17.55 times, and the nanohole model improves transmittance by up to 1.07 times. To further enhance the transmittance, a defect design in localized regions is proposed, enabling light to escape at more favorable angles and reducing the impact of total internal reflection, thereby improving transmittance. The defect model shows a 0.9% improvement compared to the nanocone model. For detectors, the increased transmittance can help medical imaging systems capture subtle lesions or tissue changes more clearly in low-light environments. In environmental monitoring, it enables more precise identification of small signal variations. These findings not only provide theoretical support for the development of high-performance optical devices but also offer important guidance for optimization.