Unlocking the Core Geometry of High-Efficiency Copper Iodide Cluster Scintillators

Area of Science:

• Materials Science
• Solid-State Chemistry
• Radiochemistry

Background:

• Copper(I) halide emitters are explored for X-ray imaging due to efficient emission and low toxicity.
• Understanding the role of Cu-I core architecture in ultrafast energy conversion is crucial for improving scintillation efficiency.

Purpose of the Study:

• To investigate the influence of core geometry on the radioluminescence (RL) behavior and efficiency of zero-dimensional copper(I) iodide clusters.
• To establish structure-property relationships for designing advanced scintillators.

Main Methods:

• Synthesized a series of zero-dimensional copper(I) iodide clusters (monomer, dimer, cubane tetramer) using a unified ligand strategy.
• Systematically studied photoluminescence quantum yield (PL QY) and radioluminescence (RL) properties.
• Analyzed exciton relaxation pathways through low-temperature PL-RL difference spectroscopy.

Main Results:

• All synthesized clusters demonstrated near-unity photoluminescence quantum yield (PL QY).
• Core geometry significantly affects thermal stability and exciton relaxation dynamics.
• A novel exciton relaxation channel was identified in cubane clusters, directly populating the 3CC state, enhancing exciton confinement and transfer.

Conclusions:

• The core geometry of Cu-I clusters is a critical factor in determining scintillation efficiency.
• Cubane cluster architecture facilitates efficient exciton confinement and radiative recombination, paving the way for high-performance scintillators.
• This work provides fundamental insights into scintillation mechanisms and guides the design of next-generation X-ray imaging materials.