[Preparation and Performance of Ultrafast γ-CuI Scintillation Conversion Screen]

Area of Science:

• Materials Science
• Solid State Physics
• Optoelectronics

Context:

• Developing efficient scintillation screens is vital for X-ray detection and imaging.
• Micro-columnar structures offer potential advantages in scintillation performance.
• Gamma-copper(I) iodide (γ-CuI) is a promising material for scintillation applications.

Purpose:

• To investigate the effect of substrate temperature on the properties of micro-columnar γ-CuI scintillation screens.
• To correlate structural characteristics with luminescence and spatial resolution.
• To optimize fabrication parameters for improved screen performance.

Summary:

• Micro-columnar γ-CuI scintillation screens (17 µm thick) were fabricated via thermal evaporation at varying substrate temperatures (170-210 °C).
• X-ray luminescence showed a dominant fast emission at 430 nm, with intensity decreasing and a slow emission near 700 nm increasing at higher temperatures, attributed to iodine loss.
• Rutherford backscattering confirmed iodine loss. Crystal structure maintained (111) preferred orientation, with additional peaks appearing at 210 °C.
• Scanning electron microscopy revealed improved columnar structure from 170 °C to 190 °C, degenerating at 210 °C.
• Spatial resolution was measured using the knife-edge method, achieving 4.5, 7.2, and 5.6 lp·mm⁻¹ at 170, 190, and 210 °C, respectively.

Impact:

• The study demonstrates that micro-columnar structures significantly enhance the spatial resolution of γ-CuI scintillation screens.
• Optimizing substrate temperature during fabrication is critical for controlling structural integrity and luminescence properties.
• Findings provide insights for designing high-performance scintillation detectors for various X-ray imaging applications.