High-Performance MDABCO-NH4(BF4)3 Single Crystals for Rapid Real-Time Charged Particle Detection and Tissue-Equivalent X-ray Imaging

Abstract

Achieving real-time, high-sensitivity radiation detection with stability and precision remains a critical challenge in medical diagnostics and radiation therapy. Here, we report the development of MDABCO-NH₄(BF₄)₃ single crystals (SCs), a metal-free perovskite material with exceptional performance for both X-ray and charged particle detection. Large-scale MDABCO-NH₄(BF₄)₃ SCs (15 × 13 × 5 mm³) were synthesized via a simple low-temperature solution method, achieving superior crystallinity with a full width at half-maximum (fwhm) of 0.0061°. The MDABCO-NH₄(BF₄)₃ detectors exhibit high resistivity (1.31 × 10¹² Ω·cm), low trap density (1.09 × 10⁹ cm^–3), and excellent charge transport properties ((μτ)_h = 3.15 × 10^–5 cm²·V^–1). For α-particle detection, the MDABCO-NH₄(BF₄)₃ detectors achieve a high energy resolution of 35.0% at 5.49 MeV and a fast response time of 5 ms, demonstrating single-particle sensitivity. For X-ray detection, MDABCO-NH₄(BF₄)₃ detectors exhibit high sensitivity (13,529 μC·Gy_abs^–1·cm^–2) and an ultralow detection limit (17.1 nGy_air·s^–1), significantly lower than the 5.5 μGy_air·s^–1 standard for active personal dosimeters used in regular medical diagnostics. The combination of superior charge transport properties with stability and high signal-to-noise ratio establishes MDABCO-NH₄(BF₄)₃ SCs as a versatile material for real-time radiation monitoring and high-precision medical imaging applications.