Lattice anchoring stabilizes α‑FAPbI3 perovskite for high‑performance X‑ray detectors

As demand grows for high-performance, low-cost X-ray detectors in medical imaging, security screening, and industrial inspection, traditional materials like α-Se and CdZnTe face limitations in sensitivity, stability, or scalability. Now, researchers from Sun Yat-sen University, led by Professor Xu-Dong Wang and Professor Dai-Bin Kuang, have developed a groundbreaking lattice-anchoring strategy using low-dimensional perovskite to stabilize α-FAPbI₃, enabling ultra-sensitive and stable X-ray detection.

Why This Breakthrough Matters

• Enhanced Structural Stability: The lattice-matched (HtrzT)PbI₃ layer mitigates tensile strain in α-FAPbI₃, suppressing phase transitions and improving long-term stability.
• Superior Charge Transport: Strengthened Pb–I bonding and reduced defect density significantly boost carrier mobility and lifetime, critical for high-sensitivity detection.
• Low-Dose Detection: The resulting detector achieves a remarkable sensitivity of 1.83×10⁵ μC Gyₐᵢᵣ^-1 cm^-2 and a detection limit as low as 27.6 nGyₐᵢᵣ s^-1—far exceeding current medical imaging standards.

Innovative Design and Features

• Lattice Matching Strategy: A conjugated organic cation (HtrzT⁺) forms a low-dimensional perovskite that coherently interfaces with α-FAPbI₃, reducing lattice mismatch to <3%.
• Defect Passivation: The thiol group in HtrzT⁺ coordinates with undercoordinated Pb²⁺ ions, passivating traps and enhancing optoelectronic properties.
• Scalable Fabrication: Blade-coating and hot-pressing techniques enable uniform, large-area (10×10 cm²) thick films suitable for flat-panel X-ray imagers.

Applications and Future Outlook

• High-Resolution Imaging: The detector demonstrates clear X-ray imaging under both soft and hard X-ray energies, with excellent contrast and spatial resolution.
• Radiation Hardness: Stable performance under prolonged irradiation (equivalent to 1.17 million chest scans) highlights its potential for continuous-use medical devices.
• Commercial Viability: The low-cost, solution-processable material system and scalable fabrication route pave the way for next-generation X-ray imagers and security scanners.

This work presents a transformative approach to stabilize α-FAPbI₃ perovskites for high-performance X-ray detection. It opens new avenues for developing stable, sensitive, and cost-effective perovskite-based detectors for real-world imaging applications. Stay tuned for more innovations from Professor Wang and Professor Kuang’s team at Sun Yat-sen University!