Wednesday 19 March 2025
Scientists have been working tirelessly to develop new technologies that can withstand the harsh conditions of space and high-energy particle collisions. One such technology is the silicon photomultiplier (SiPM), a device used to detect light in various applications, including astronomy and medical imaging.
Recently, researchers from École Polytechnique Fédérale de Lausanne (EPFL) have made significant progress in developing SiPMs that can operate at extremely low temperatures. The team has successfully tested two different types of SiPM arrays, produced by Fondazione Bruno Kessler (FBK) and Hamamatsu Photonics, under cryogenic conditions.
The study focused on evaluating the performance of these SiPM arrays as they cooled from room temperature to 100 Kelvin (-173°C). At such low temperatures, the devices’ electrical properties can change significantly, potentially affecting their ability to detect light. The researchers were interested in understanding how these changes might impact the SiPMs’ performance and whether they could still be used effectively.
One key finding was that the breakdown voltage of the SiPM arrays decreased linearly with temperature until around 200 Kelvin (-73°C). Below this point, the decrease became less pronounced and even seemed to level off. This information is crucial for designing and operating these devices, as it allows scientists to optimize their performance at cryogenic temperatures.
Another significant discovery was that the quenching resistor, a critical component in SiPMs, increased its value significantly at low temperatures. This change can affect the recovery time of the device, which is essential for applications where precise timing is required. The researchers noted that this increase could be beneficial for some uses but might require adjustments to achieve optimal performance.
The team also examined the photon detection efficiency (PDE) and gain of the SiPM arrays as a function of temperature. Surprisingly, they found that the PDE remained constant within uncertainties across the entire temperature range studied. This stability is critical in applications where precise light detection is necessary. The gain of the devices did show some variations with temperature, but these changes were relatively small.
Finally, the researchers investigated the direct cross-talk probability (DiXT) of the SiPM arrays at different temperatures. DiXT occurs when a photon triggers multiple pixels in an array, potentially leading to errors or false signals. The study revealed that DiXT decreased slightly with cooling for one type of SiPM and increased by around 20% for the other.
Cite this article: “SiPM Performance Under Cryogenic Conditions: Temperature-Dependent Properties Revealed”, The Science Archive, 2025.
Silicon Photomultiplier, Space Technology, Cryogenic Temperature, Sipm Arrays, Photon Detection Efficiency, Gain, Quenching Resistor, Breakdown Voltage, Direct Cross-Talk Probability, Low-Temperature Operation.
