Semiconducting Organic Metal Halide Complex Glasses for Efficient X-Ray Detection.

Area of Science:

• Materials Science
• Solid-State Physics
• Medical Imaging Technology

Background:

• Growing demand for efficient, low-cost, and scalable direct X-ray detectors.
• Limitations of conventional inorganic semiconductors (e.g., Si, α-Se, Cd(Zn)Te) and organic semiconductors (sensitivity, energy resolution, detection limits).
• Need for novel materials with improved performance for X-ray detection.

Purpose of the Study:

• To demonstrate the first direct X-ray detectors based on organic metal halide complexes (OMHCs).
• To investigate the performance of OMHCs in their glassy form for X-ray detection applications.
• To establish OMHC glasses as a viable new material class for high-performance X-ray detectors.

Main Methods:

• Synthesis of organic metal halide complexes (OMHCs), specifically 4-(4-(diphenylamino) phenyl)-1-(propyl)-pyridinium zinc bromide ((TPA-Py)₂ZnBr₂).
• Fabrication of glassy OMHC samples using a facile melt-processing approach from wet-chemistry-synthesized single crystals.
• Device fabrication and characterization of direct X-ray detectors using the glassy OMHC material.

Main Results:

• Achieved high dark resistivity of 5.37 × 10¹¹ Ω cm for the glassy OMHC material.
• Demonstrated excellent detection sensitivity of 2,020 µC Gyair⁻¹ cm⁻² at 10 V mm⁻¹ electric field.
• Obtained an ultralow detection limit of 12.44 nGyair s⁻¹.

Conclusions:

• Semiconducting OMHC glasses represent a novel and highly promising material class for direct X-ray detection.
• The developed OMHC-based detectors exhibit outstanding performance characteristics, surpassing limitations of existing organic materials.
• The facile melt-processing approach enables scalable fabrication of air-stable glassy samples for device integration.