Efficient Direct X-ray Detection and Imaging Based on a Lead-Free Electron Donor-Acceptor MOF

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Metal-organic frameworks (MOFs) show promise for radiation detection due to their unique properties.
• Developing practical MOF-based X-ray detectors with high efficiency, stability, and environmental friendliness remains a challenge.
• Integrating donor-acceptor (D-A) pairs into MOFs offers a strategy for creating advanced optoelectronic materials.

Purpose of the Study:

• To design and synthesize a novel lead-free MOF using a D-A strategy for X-ray detection.
• To evaluate the X-ray detection performance, stability, and potential for imaging applications of the synthesized MOF.
• To develop flexible composite X-ray detector films based on the MOF for practical applications.

Main Methods:

• Synthesis of a new lead-free MOF, Cu2I2(TPPA) (CuI-TPPA), utilizing a D-A approach.
• Characterization of the MOF's structure and optoelectronic properties, including mobility-lifetime product.
• Fabrication and testing of CuI-TPPA based X-ray detector films and pixelated detectors.

Main Results:

• The synthesized CuI-TPPA MOF exhibits a high mobility-lifetime product (5.8 × 10⁻⁴ cm² V⁻¹) and detection sensitivity (73.1 μC Gyair⁻¹ cm⁻²).
• The detector demonstrated excellent stability, with only a 2% photocurrent reduction after significant radiation exposure (>42.83 Gyair).
• Flexible composite films achieved a high sensitivity of 143.6 μC Gyair⁻¹ cm⁻², and pixelated detectors successfully realized X-ray direct imaging.

Conclusions:

• The novel lead-free CuI-TPPA MOF is a promising material for high-performance direct X-ray detection.
• The developed flexible composite films and pixelated detectors demonstrate the potential for environmentally friendly and wearable X-ray imaging devices.
• This research opens new avenues for MOF applications in advanced radiation detection technologies.