Centimeter-Sized CsPbBr₃ Single-Crystal Films for Energy-Resolved Radiation Detection

Area of Science:

• Materials Science
• Radiation Detection Physics

Background:

• Metal halide perovskites (MHPs) are emerging materials for radiation detection applications.
• Single crystals (SCs) offer superior properties over polycrystalline films, including lower defect density and higher carrier mobility.
• Synthesizing large-area MHP SCs for imaging detectors presents significant challenges.

Purpose of the Study:

• To develop a method for growing high-quality, centimeter-sized CsPbBr3 single crystals.
• To investigate the material properties and radiation detection performance of these CsPbBr3 SCs.
• To evaluate the potential of these SCs for large-area flat panel imaging detectors.

Main Methods:

• Employed a space-confined inverse temperature method to grow CsPbBr3 SCs with thicknesses ranging from 0.25 mm to 1 mm.
• Incorporated choline bromide into the precursor solution to enhance material quality.
• Fabricated spectral detectors and a prototype 3x3 pixelated detector for performance evaluation.

Main Results:

• Achieved centimeter-sized CsPbBr3 SCs with reduced defect density and suppressed ion migration.
• Obtained high resistivity (2.5 × 10^10 Ω cm) and a high mobility-lifetime product (> 1 × 10^-3 cm^2 V^-1).
• Demonstrated excellent energy resolution for X-ray (14.96% at 59.5 keV) and alpha particles (15.95% at 5.48 MeV).

Conclusions:

• The developed method enables the growth of high-quality, large-area CsPbBr3 SCs suitable for radiation detection.
• The enhanced material properties translate to superior spectral detector performance.
• These CsPbBr3 SCs are highly promising for developing next-generation, high-resolution flat panel imaging detectors.