Modeling of afterpulsing in Single-Photon Avalanche Diodes

The afterpulsing noise in Single-Photon Avalanche Diodes (SPADs) is modeled and investigated in order to evaluate its impact on SPAD performance, in terms of maximum count rate, signal-to-noise ratio, etc. From measurements fitting, we identified three/four types of defects that we then used to simulate the behavior of the SPAD when operated in different conditions. We show how the presented modeling is a valuable tool for the estimation of the performance of different SPADs and the identification of optimal operating conditions, in terms of temperature, voltage bias, gate width, gate repetition frequency, quenching time, etc.