Device testing of VUV SiPMs for nEXO

The tonne-scale nEXO experiment aims to search for neutrinoless double beta decay with a half-life sensitivity of ~10²⁸ years. The nEXO detector is a liquid xenon time projection chamber enriched to 90% ¹³⁶Xe that uses vacuum ultraviolet (VUV) silicon photomultipliers (SiPMs) as scintillation sensors. This talk will cover the testing of the SiPM devices that are under consideration for use in nEXO. We present the characterization methods and results, focusing on the photon detection efficiency (PDE), single photoelectron (SPE) gain, temperature-dependent breakdown voltage, dark count rate, and correlated avalanche contribution.