X-ray and γ-ray Sensing from Aqueous-Based Lead Sulfide Telluride Nanocomposites

Area of Science:

• Materials Science
• Semiconductor Physics
• Nanotechnology

Background:

• Lead chalcogenides (PbS, PbSe, PbTe) possess unique properties like high charge mobility, making them suitable for energetic quantum sensing.
• Existing fabrication methods limit the creation of large-volume networks needed for practical applications.
• High intrinsic energy resolution is achievable at room temperature due to de-coupled electronic and phononic modes.

Purpose of the Study:

• To develop a simple and effective fabrication procedure for large-volume percolating networks of lead chalcogenides.
• To enhance the performance of X-ray and gamma-ray sensors using these novel materials.
• To explore the potential of these composites for secondary electron stopping and radiation shielding.

Main Methods:

• A synthesis strategy using aqueous colloids of PbS_xTe_y nanoparticles.
• Grafting nanoparticles onto an aramid nanofiber scaffold to create size-scalable solids.
• Characterization of charge transport and energy resolution of the resulting composite materials.

Main Results:

• Achieved excellent charge transport throughout the size-scalable composite solids.
• Demonstrated an energy resolution for X-ray and γ-ray sensing equivalent to commercial single-crystalline cadmium telluride detectors (2.8 keV at 81 keV).
• Observed enhanced stopping of secondary electrons due to interfaces and lattice planes, enabling thin-film stopping layers and flexible shielding.

Conclusions:

• The reported synthesis strategy successfully overcomes fabrication limitations for lead chalcogenide networks.
• The nanoparticle-polymeric composite offers high-performance sensing capabilities for energetic quanta.
• The material shows promise for diverse applications including X-ray/gamma-ray detection and lightweight radiation shielding.