Lead-Free Perovskite Single Crystal Linear Array Detector for High-Resolution X-Ray Imaging.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Semiconductor Physics

Background:

• 0D Bi-based 329-type halide perovskites show promise for X-ray detection due to strong absorption and stability.
• Low mobility-lifetime product (µτ) in these materials hinders detection sensitivity improvements.

Purpose of the Study:

• To design a novel 2D Bi-based 329-type halide perovskite with enhanced properties for X-ray detection.
• To overcome the limitations of existing lead-free perovskite X-ray detectors.

Main Methods:

• First-principles calculations were used to design the new 2D perovskite structure.
• A mixed-halide-induced structural dimension regulation strategy was employed.
• High-quality, inch-sized single crystals (SCs) were grown using a continuous precursor solution supply.

Main Results:

• The new 2D Bi-based SCs exhibit a significantly enhanced µτ product, high resistivity, and low ion migration.
• Fabricated detectors achieved a record X-ray detection sensitivity of 24,509 µC Gy_air^-1 cm^-2.
• The detectors demonstrated a low detection limit (4.3 nGy s^-1), fast response time (315 µs), and excellent stability, comparable to lead-based detectors.

Conclusions:

• The developed 2D Bi-based halide perovskites represent a breakthrough in lead-free X-ray detection technology.
• These materials offer superior performance and stability, outperforming existing lead-free options.
• The findings are expected to drive the development of a new generation of advanced X-ray detectors.