Characterization of New Silicon Photomultipliers with Low Dark Noise at Low Temperature

TL;DR

This paper presents a new silicon photomultiplier with significantly reduced dark count rate at low temperatures, making it more suitable for dark matter detection in liquid xenon experiments.

Contribution

A novel SiPM design with lowered electric field strength that substantially reduces dark noise at cryogenic temperatures.

Findings

6-54 times lower dark count rate at low temperatures

Effective suppression of band-to-band tunneling effects

Potential for improved dark matter detection sensitivity

Abstract

Silicon photomultipliers (SiPMs) have a low radioactivity, compact geometry, low operation voltage, and reasonable photo-detection efficiency for vacuum ultraviolet light (VUV). Therefore it has the potential to replace photomultiplier tubes (PMTs) for future dark matter experiments with liquid xenon (LXe). However, SiPMs have nearly two orders of magnitude higher dark count rate (DCR) compared to that of PMTs at the LXe temperature ($\sim$ 165 K). This type of high DCR mainly originates from the carriers that are generated by band-to-band tunneling effect. To suppress the tunneling effect, we have developed a new SiPM with lowered electric field strength in cooperation with Hamamatsu Photonics K. K. and characterized its performance in a temperature range of 153 K to 298 K. We demonstrated that the newly developed SiPMs had 6--54 times lower DCR at low temperatures compared to that of the conventional SiPMs.