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arXiv · 2507.18172

Silicon single-photon detector achieving over 84% photon detection efficiency with flexible operation modes

Abstract

Silicon single-photon detectors (Si SPDs) play a crucial role in detecting single photons in the visible spectrum. For various applications, photon detection efficiency (PDE) is the most critical characteristic for effectively collecting photons. Here, we present a Si SPD with a remarkable PDE of up to 84.4% at 785 nm, supporting multiple operation modes. We design and fabricate a thick-junction Si single-photon avalanche diode (SPAD) that enhances the avalanche probability through a backside-illumination structure, while minimizing noise through the design of a doping-compensated avalanche region. To maximize PDE, we implement a readout circuit with a 50 V quenching voltage, enabling operation in free-running, gating, or hybrid modes. The SPAD, along with its readout circuits and affiliated circuits, is integrated into a compact SPD module. In free-running mode, the module achieves a maximum PDE of 84.4%, with a dark count rate of 260 cps, and an afterpulse probability of 2.9% at 268 K. This work provides a practical solution for applications requiring ultra-high-efficiency Si SPD with multiple operation modes.

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Dong An, Chao Yu, Ming-Yang Zheng, Anran Guo, Junsong Wang, Ruizhi Li, Huaping Ma, Xiu-Ping Xie, Xiao-Hui Bao, Qiang Zhang, Jun Zhang, Jian-Wei Pan. 2025-07-24. Silicon single-photon detector achieving over 84% photon detection efficiency with flexible operation modes. https://arxiv.org/abs/2507.18172

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