Solution-grown BiI/BiI₃ van der Waals heterostructures for sensitive X-ray detection.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Detector Technology

Background:

• X-ray detectors require high sensitivity and low detection limits for safe medical and security applications.
• Organolead trihalide perovskites show promise but pose environmental and health risks due to lead content.

Purpose of the Study:

• To develop highly sensitive and environmentally friendly X-ray detectors.
• To explore the potential of bismuth iodide (BiI) van der Waals heterostructures for X-ray detection.

Main Methods:

• Solution-growth of thick BiI/BiI₃/BiI (Bi_xI_y) van der Waals heterostructures.
• Fabrication and characterization of X-ray detectors based on these heterostructures.
• Evaluation of detector sensitivity, detection limit, and stability.

Main Results:

• Demonstrated anisotropic X-ray detection response.
• Achieved high sensitivity up to 4.3 × 10⁴ μC Gy^-1 cm^-2.
• Obtained a low detection limit of 34 nGy s^-1.
• Exhibited high environmental and radiation stability.

Conclusions:

• Bi_xI_y van der Waals heterostructures are effective for high-performance, lead-free X-ray detection.
• This work encourages the development of new van der Waals heterostructures for safer optoelectronic devices.
• The findings support the use of bismuth-based materials as alternatives in radiation detection.