Abstract Gamma-ray spectroscopy that quantifies the gamma-ray energies is a critical technology widely needed in astrophysics, nuclear material detection and medical treatment. The key is to precisely count gamma-ray photons using sensitive detectors. In this paper, we investigate the operational principles of chlorine-doped methylammonium lead tribromide (MAPbBr3−xClx) perovskite single crystal detectors that can efficiently count gamma-ray photon events with electrical pulses. Specifically, we find the main dark current originates from the thermally activated electron injection from the impurities, and using high work function contacts can block out the dark noise thus allows for efficient pulse collection at higher electrical fields ∼500 V/cm. As a result, we observe strong electrical pulses when exposing the detector under radioactive sources emitting gamma-ray photons at various energies. Our results also reveal the fundamental issues that prevent the reliable observation of photo-electric peak. This work suggest pathway towards energy resolved gamma-ray spectroscopy using perovskite crystal detectors.

中文翻译：

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混合钙钛矿伽马射线光子计数器的工作原理

摘要 量化伽马射线能量的伽马射线光谱是天体物理学、核材料探测和医疗领域广泛需要的一项关键技术。关键是使用灵敏的探测器精确计算伽马射线光子。在本文中，我们研究了掺氯甲基铵三溴化铅 (MAPbBr3−xClx) 钙钛矿单晶探测器的工作原理，该探测器可以通过电脉冲有效地计数伽马射线光子事件。具体来说，我们发现主要的暗电流来自杂质的热激活电子注入，使用高功函数触点可以阻挡暗噪声，从而允许在更高的电场 ~500 V/cm 下有效地收集脉冲。因此，当将探测器暴露在以各种能量发射伽马射线光子的放射源下时，我们观察到强电脉冲。我们的结果还揭示了妨碍可靠观察光电峰的根本问题。这项工作提出了使用钙钛矿晶体探测器实现能量分辨伽马射线光谱的途径。