NUV Silicon Photomultipliers With High Detection Efficiency and Reduced Delayed Correlated-Noise

In this paper, we present the characteristics and performances of new silicon photomultipliers (SiPMs), produced at FBK, for the near-ultraviolet (NUV) light detection, with reduced afterpulsing and delayed optical crosstalk. To study these components of the correlated noise, we manufactured SiPMs on silicon wafers featuring different substrate minority-carrier lifetime. This parameter proved to be crucial in determining the amount of delayed optical crosstalk and afterpulsing caused by photo-generated carriers diffusing from the substrate to the cell active region. With a very low substrate lifetime, we were able to minimize this correlated noise component to few percent at room temperature. Besides reducing the excess noise factor, the lower delayed correlated noise allows biasing the SiPM at higher voltages, reaching higher values of photon detection efficiency.