New Developments of Near-UV SiPMs at FBK

A thorough characterization of a novel silicon photomultiplier technology for near-ultraviolet (near-UV) light detection, called NUV-SiPM, is presented. It features a peak detection efficiency of more than 30% in the region between 380 and 400 nm, mainly limited by the fill factor. An accurate electric field engineering allows to have excellent noise properties, with a dark count rate of less than 200 kHz/mm² at maximum efficiency and 20^°C. In addition, a breakdown voltage uniformity better than 100 mV at the wafer level and a temperature dependence of 25 mV/^°C were obtained. We coupled a 4 × 4 mm² device to a 3 × 3 × 5 mm³ LYSO scintillator obtaining an energy resolution of 10% FWHM with 511-keV gamma ray irradiation and a coincidence resolving time between two identical detectors of 210-ps FWHM. A detailed description of these results is presented in the paper.