Temperature-Inert Coinage Metal Cluster Scintillator.

Area of Science:

• Materials Science
• Radiological Imaging
• Luminescence

Background:

• Scintillators convert ionizing radiation to photons but are typically temperature-sensitive, limiting their applications.
• Radioluminescence intensity often decreases significantly with increasing temperature.

Purpose of the Study:

• To develop a temperature-inert scintillator material.
• To investigate the luminescence mechanism of the new material.
• To demonstrate its application in high-resolution X-ray imaging.

Main Methods:

• Preparation of a coinage metal cluster scintillator (Cu4S).
• Characterization of radioluminescence intensity across a wide temperature range (80–450 K).
• Mechanism study involving thermally activated delayed fluorescence (TADF) and C–H···π interactions.
• Fabrication of a flexible scintillator screen using Cu4S and polydimethylsiloxane (PDMS).
• Performance evaluation of the scintillator screen in X-ray imaging.

Main Results:

• Cu4S exhibited intense radioluminescence with minimal fluctuations from 80 to 450 K.
• Mechanism revealed restricted geometric relaxation and small reorganization energy, leading to temperature-independent luminescence.
• Cu4S demonstrated excellent water, oxygen, and thermal stability.
• A flexible Cu4S-PDMS scintillator screen achieved high-resolution X-ray imaging (above 20 LP mm⁻¹) with stable performance across temperatures.

Conclusions:

• Cu4S is a promising temperature-inert scintillator material with TADF properties.
• The material's stability and unique luminescence behavior enable robust, high-resolution X-ray imaging applications.
• This work overcomes temperature-dependent limitations in scintillator technology.