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

Abstract

Metal halide perovskites (MHPs) are promising materials for radiation detection. Compared with polycrystalline films, single crystals (SCs) have lower defect density, higher carrier mobility, and lifetime. However, the direct synthesis of MHP SCs for large-area flat panel imaging detectors remains challenging. Here, we show that high-quality centimeter-sized CsPbBr₃ SCs with thicknesses between 0.25 mm and 1 mm can be grown by a space-confined inverse temperature method. The addition of choline bromide to the precursor solution reduces the defect density and suppresses ion migration of the CsPbBr₃ SCs, leading to a high resistivity of 2.5 × 10¹⁰ Ω cm and a high mobility-lifetime product of over 1 × 10^-3 cm² V^-1. The CsPbBr₃ SC spectral detectors exhibit an energy resolution of 14.96% for ²⁴¹Am 59.5 keV X-ray and 15.95% for 5.48 MeV α-particles. Moreover, a prototype 3 × 3 pixelated detector based on the large-area SC shows a consistent high performance for all pixels, making it promising for high-resolution flat panel imaging detectors.

Keywords: X-ray detectors; energy resolution; halide perovskites; radiation detectors; single crystals.