Qin Haoming, Xiao Bao, He Xuchang, Ouyang Xiao, Gao Tingting, Wang Yuquan, Wang Luyao, Sun Qihao, Shen Nannan, Ouyang Xiaoping, He Yihui
State Key Laboratory of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, and School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University, Suzhou, China.
Key Laboratory of Beam Technology of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing, China.
Nat Commun. 2025 Jan 2;16(1):158. doi: 10.1038/s41467-024-55561-8.
High intrinsic detection efficiency is as decisive as high energy resolution. Scaling up detector volume has presented great challenges, preventing perovskite semiconductors from reaching sufficient detection efficiency. We report a hole-only virtual-Frisch-grid CsPbBr detector up to 2.2 cm thick for efficient gamma-ray spectroscopy. By utilizing high-quality columnar CsPbBr single crystals up to ~1 cm, we configure virtual-Frisch-grid detectors with optimized weighting potential distribution. These centimeter-thick detectors outperform ambipolar planar configuration, achieving a champion energy resolution of 1.9% at 662 keV. Time-of-flight analysis, stimulated by single gamma-ray photon, reveals hole carrier multiplication effect possibly caused by Auger recombination and space charge accumulation effect, collectively driving an anomalous stabilization process. Digital pulse measurements reduce the ballistic deficit, thereby improving the spectral response to 2.2% at 662 keV for 2.2 cm thick detector. The low-cost device fabrication and adequate detection efficiency of virtual-Frisch-grid detectors will surely foster the development of large-volume perovskite detectors.
高本征探测效率与高能量分辨率同样重要。扩大探测器体积面临巨大挑战，这使得钙钛矿半导体难以达到足够的探测效率。我们报道了一种仅空穴的虚拟-弗里施栅 CsPbBr 探测器，其厚度达 2.2 厘米，用于高效的伽马射线能谱分析。通过使用高达约 1 厘米的高质量柱状 CsPbBr 单晶，我们配置了具有优化加权电位分布的虚拟-弗里施栅探测器。这些厘米厚的探测器性能优于双极性平面配置，在 662 keV 处实现了 1.9%的最佳能量分辨率。由单个伽马射线光子激发的飞行时间分析揭示了可能由俄歇复合和空间电荷积累效应引起的空穴载流子倍增效应，共同推动了一个异常的稳定过程。数字脉冲测量减少了弹道亏损，从而将 2.2 厘米厚探测器在 662 keV 处的能谱响应提高到 2.2%。虚拟-弗里施栅探测器的低成本器件制造和足够的探测效率必将推动大体积钙钛矿探测器的发展。
