Delayed avalanches in Multi-Pixel Photon Counters
Delayed avalanches in Multi-Pixel Photon Counters
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DOI：
10.1088/1748-0221/12/07/p07026
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发表时间：
2017-07-01
影响因子：
1.3
通讯作者：
Rethmeier, C.
中科院分区：
文献类型：
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作者：
Boone, K.;Iwai, Y.;Rethmeier, C.
Hamamatsu Photonics 于 2013 年推出了新一代多像素光子计数器，显着降低了后脉冲率。在本文中，我们通过使用 405 至 820 nm 范围的激光测试 2013 年之前和 2013 年之后的设备来调查后脉冲的原因。通过这样做，我们研究了后脉冲也是由于雪崩中产生的光学光子而不是杂质捕获雪崩中产生的带电载流子并在稍后释放它们的可能性。对于 2013 年之前的器件，我们在 637、777 nm 和 820 nm 处观察到雪崩延迟 ns 至数百 ns，这表明在硅块的零场区域中产生的空穴可以扩散回高场区域，从而触发延迟雪崩。另一方面，2013 年之后在 777 nm 处没有表现出超过 100 ns 的延迟雪崩。我们还确认 2013 年之后的器件后脉冲降低了约 25 倍。总而言之，我们的测量结果表明，硅体中雪崩吸收的光子以及随后空穴扩散回结的现象是 2013 年之前器件的后脉冲的重要来源。在我们的初步结果发布后，滨松似乎在 2013 年解决了这个问题。我们还表明，即使在短波长下，定时分布也会在亚纳秒范围内表现出尾部，这可能会损害 MPPC 定时性能。
Hamamatsu Photonics introduced a newgeneration of their Multi-Pixel Photon Counters in 2013 with significantly reduced after-pulsing rate. In this paper, we investigate the causes of after-pulsing by testing pre-2013 and post-2013 devices using laser light ranging from 405 to 820 nm. Doing so we investigate the possibility that afterpulsing is also due to optical photons produced in the avalanche rather than to impurities trapping charged carriers produced in the avalanches and releasing them at a later time. For pre-2013 devices, we observe avalanches delayed by ns to several 100 ns at 637, 777 nm and 820 nm demonstrating that holes created in the zero field region of the silicon bulk can diffuse back to the high field region triggering delayed avalanches. On the other hand post-2013 exhibit no delayed avalanches beyond 100 ns at 777 nm. We also confirm that post-2013 devices exhibit about 25 times lower after-pulsing. Taken together, our measurements show that the absorption of photons from the avalanche in the bulk of the silicon and the subsequent hole diffusion back to the junction was a significant source of after-pulse for the pre-2013 devices. Hamamatsu appears to have fixed this problem in 2013 following the preliminary release of our results. We also show that even at short wavelength the timing distribution exhibit tails in the sub-nanosecond range that may impair the MPPC timing performances.