Physics of Single Photon Avalanche Detectors With Built-In Self-Quenching and Self-Recovering Capabilities

A single photon avalanche detector featuring a transient carrier buffer layer to form an energy barrier that tentatively stops avalanche-generated carriers, demonstrates self-quenching and self-recovering capabilities. The escape rate of those stopped avalanche carriers from the barrier determines the self-recovery time and thus the count rate of the single photon detector. A physical model has been developed to simulate the dynamic characteristics of the detector. The simulation results agree well with the experimental data, and the self-recovery time is found to be reduced with the increase of the temperature and the overbias magnitude as well as the decrease of the dosage in the charge layer and the barrier height. In addition, thermionic emission shows a stronger dependence on temperature and a weaker dependence on device bias and charge layer dosage than tunneling. The model contains no fitting parameters and therefore can be used to model and predict the device behaviors.