High-Quality Perovskite Films Enabled by Solution-Processed Vacuum Evaporation for Flexible PIN-Type X-Ray Detectors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Medical Imaging

Background:

• Flexible X-ray detectors are crucial for portable medical imaging and wearable electronics.
• Current manufacturing methods face challenges in balancing performance, flexibility, and scalability.
• Solution-based and vacuum evaporation techniques have limitations in film quality, cost, and throughput.

Purpose of the Study:

• To develop an optimized, scalable, and cost-effective method for fabricating high-quality perovskite films on flexible substrates.
• To investigate the structure-property relationships of different perovskite material systems for X-ray detection.
• To demonstrate the performance and mechanical robustness of flexible X-ray detectors based on the developed fabrication strategy.

Main Methods:

• An optimized solution-processed vacuum evaporation strategy was employed.
• Tailored additives and controlled vapor-phase conversion kinetics were used to improve film quality.
• Three perovskite systems (MAPbI₃, MAPb(IBr)₃, CsMAPb(IBr)₃) were systematically investigated.
• Flexible PIN-type X-ray detectors were fabricated and characterized.

Main Results:

• High-quality perovskite films (~1 μm thick) were fabricated on flexible PEN substrates at 100 °C.
• Significant improvements in film density, crystallinity, and uniformity were achieved.
• The CsMAPb(IBr)₃-based detector showed a low dark current density (5.2 nA cm⁻²) and high sensitivity (1.43 × 10⁴ μC·Gyair⁻¹·cm⁻²).
• The detector maintained over 95% performance after 400 bending cycles (6 mm radius).

Conclusions:

• The developed method offers a viable, cost-effective route for scalable production of high-performance flexible X-ray detectors.
• The findings address critical challenges in advancing next-generation portable imaging technologies.
• The demonstrated mechanical robustness and durability are promising for practical applications.