Interstitial Copper Doping in Cs₃Bi₂Br₉: A Pathway to Enhanced Radiation Detection Performance.

Area of Science:

• Materials Science
• Solid-State Physics
• Optoelectronics

Background:

• Double perovskites offer tunable optoelectronic properties for advanced applications.
• Cation transmutation is a strategy to modify material characteristics.
• Bismuth halide perovskites are being explored as alternatives to lead-based materials.

Purpose of the Study:

• To investigate the effect of copper (Cu) doping on the X-ray detection performance of Cs3Bi2Br9 perovskites.
• To explore the role of interstitial Cu+ ions in modifying defect properties and carrier transport.
• To assess the potential of these doped perovskites for radiation detection and medical applications.

Main Methods:

• Cation transmutation by substituting silver (Ag) with copper (Cu) in a double halide perovskite structure.
• Characterization of the resulting material's structure and properties.
• Evaluation of X-ray and alpha-particle detection performance, including sensitivity, limit of detection, and stability.
• Assessment of performance under high-energy photon irradiation from a clinical linear accelerator.

Main Results:

• Copper did not form a double halide perovskite structure but existed as interstitial dopants in the Cs3Bi2Br9 structure.
• Cu doping significantly enhanced X-ray detection sensitivity and reduced the limit of detection.
• Doped perovskites exhibited prolonged stability under continuous X-ray exposure.
• Remarkable performance was observed under irradiation from a 6 MV clinical linear accelerator.

Conclusions:

• Interstitial Cu+ ions neutralize negative defects, promoting carrier delocalization and enhancing transport in Cs3Bi2Br9.
• Copper-doped bismuth halide perovskites are promising lead-free materials for radiation dosimetry in radiotherapy and medical imaging.
• These detectors are suitable for industrial applications, especially in resource-limited or power-restricted environments.