Characteristics of Charge Persistence in InGaAs/InP Single-Photon Avalanche Diode

We present an experimental study of charge persistence effect in InGaAs/InP single-photon avalanche diodes based on their dark and illuminated characteristics. It is well known that the sources of dark carriers mainly originate from thermal generation, trap-Assisted tunneling, and afterpulsing, where these mechanisms are dominant in the dark count rate performance at different temperature ranges. In this letter, besides the above-mentioned mechanisms, we further address an additional mechanism involved that competes with suppression of thermal carriers when the temperature is decreased. A good correspondence is observed by comparing the dark characteristics with the illuminated characteristics, showing that the additional spurious signals occurred at intermediate temperature range originate from the charge persistence effect.