Fondazione Bruno Kessler (FBK) has been continuously developing and improving silicon photomultiplier technologies, for example with peak efficiency in the blue (near-ultra-violet, NUV), or in the green (red–green–blue, RGB) region of the spectrum.

Over the last years there has been a growing interest in silicon photomultipliers (SiPMs) applications at cryogenic temperatures (e.g.: for the readout of the scintillation light from liquefied noble gases in rare-events experiments). One example is the DarkSide-20k experiment, in which LAr scintillation light is detected after wavelength-shifting to match the SiPMs’ spectral response.

A dedicated silicon photomultiplier technology has been developed in FBK: the NUV-HD-Cryo. SiPMs made in such technology reach primary dark count rates of about 2 ${\mathrm{mHz∕mm}}^2$ and an after-pulsing probability of about 12% when biased at 4 V above breakdown in liquid nitrogen (LN). In other experiments, like for example the nEXO experiment, direct detection of vacuum ultra-violet (VUV) light in cryogenic conditions is required. In this case, the sensitivity in VUV has to be combined with the advantages of the “Cryo” technology.

In this contribution, the latest results from the cryogenic characterization of FBK VUV-HD technology for cryogenic temperatures will be presented. Among the produced devices, one promising split has been identified with reduced after-pulsing probability at 100 K, less than “standard” VUV-HD device.

Fondazione Bruno Kessler（FBK）一直在不断发展和改进硅光电倍增器技术，例如在蓝色（近紫外-NUV）或绿色（红-绿-蓝，RGB）区域达到峰值效率。光谱。

在过去的几年中，人们越来越关注低温下的硅光电倍增管（SiPM）应用（例如：在罕见事件实验中用于从液化稀有气体中读取闪烁光）。一个例子是DarkSide-20k实验，在该实验中，在波长偏移后检测到LAr闪烁光以匹配SiPM的光谱响应。

FBK中开发了一种专用的硅光电倍增器技术：NUV-HD-Cryo。用这种技术制造的SiPM的主要暗计数率约为2 ${\mathrm{兆赫兹·毫米}}^2$在液氮（LN）中击穿电压高于击穿电压4 V时，其后脉冲概率约为12％。在其他实验中，例如nEXO实验，需要在低温条件下直接检测真空紫外线（VUV）。在这种情况下，VUV的灵敏度必须与“ Cryo”技术的优势相结合。

在这项贡献中，将介绍FBK VUV-HD技术的低温表征在低温下的最新结果。在生产的设备中，已经确定了一种很有希望的解决方案，其在100 K下的后脉冲概率降低了，低于“标准” VUV-HD设备。