Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China.
School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
Rev Sci Instrum. 2023 Mar 1;94(3):033101. doi: 10.1063/5.0137823.
Ultraviolet single-photon detector (UVSPD) provides a key tool for applications requiring ultraweak light detection in the wavelength band. Here, we report a 4H-SiC single-photon avalanche diode (SPAD) based free-running UVSPD with ultralow afterpulse probability. We design and fabricate the 4H-SiC SPAD with a beveled mesa structure, which exhibits the characteristic of ultralow dark current. We further develop a readout circuit of passive quenching and active reset with a tunable hold-off time setting to considerably suppress the afterpulsing effect. The nonuniformity of photon detection efficiency (PDE) across the SPAD active area with a diameter of ∼180 μm is investigated for performance optimization. The compact UVSPD is then characterized, exhibiting a typical performance of 10.3% PDE, 133 kcps dark count rate, and 0.3% afterpulse probability at 266 nm. Such performance indicates that the compact UVSPD could be used for practical ultraviolet photon-counting applications.
紫外单光子探测器 (UVSPD) 为需要在波长范围内检测超弱光的应用提供了关键工具。在这里，我们报告了一种基于 4H-SiC 单光子雪崩二极管 (SPAD) 的自由运行 UVSPD，具有超低的后脉冲概率。我们设计并制造了具有斜角台面结构的 4H-SiC SPAD，其表现出超低暗电流的特性。我们进一步开发了具有可调保持时间设置的无源猝灭和有源复位的读出电路，以显著抑制后脉冲效应。我们研究了直径约为 180 μm 的 SPAD 有效面积上的光子探测效率 (PDE) 不均匀性，以优化性能。然后对紧凑型 UVSPD 进行了特性描述，在 266nm 处表现出典型的性能，包括 10.3%的 PDE、133kcps 的暗计数率和 0.3%的后脉冲概率。这种性能表明，紧凑型 UVSPD 可用于实际的紫外光子计数应用。
