Silicon Photomultipliers (SiPMs) have emerged as a compelling photosensor solution for detecting single photons in applications ranging from particle physics to medical imaging and beyond. SiPMs consist of an array of tightly packaged Single Photon Avalanche Diodes (SPADs) operated above the breakdown voltage so that they generate self sustaining charge avalanches upon absorbing an incident photon. Generally, SiPMs are a compelling photosensor solution in liquid noble gases due to their low-voltage operation, insensitivity to magnetic field, and compact and flat form factor. For these reasons, SiPMs are the adopted solution in the MEG2 and DUNE experiments. In addition, SiPMs have very low residual natural radioactivity, making them especially appealing for low-background experiments such as nEXO and DarkSide-20k.

In this talk, we will show results on the characterization of the newest vacuum ultra-violet sensitive SiPMs by Fondazione Bruno Kessler, the VUVHD3 devices specifically designed for nEXO. Moreover we will preset results on the Quality Assurance and Quality Control (QA/QC) of the production wafers made with FBK~NUV-HD-Cryo SiPMs manufactured by LFoundry s.r.l. (Avezzano, AQ, Italy) for the DarkSide-20k experiment. Various SiPM parameters, such as dark noise, gain, direct crosstalk, correlated avalanches and photon detection efficiency were measured as a function of the applied over voltage and wavelength at liquid xenon and liquid argon temperature. Finally we will briefly introduced the nEXO and DS-20k SiPM electronic with a special focus on the readout of large area SiPMs used on the just mentioned experiments.