Performance evaluation of InGaAs/InP single-photon avalanche diodes based on fitting of dark current

We analyzed the dark current characteristics of InGaAs/InP single-photon avalanche diodes (SPADs) at different bias voltages and developed a method to evaluate SPAD material quality. We performed dark current and dark count experiments on two sample device groups. By sub-area fitting dark current experimental data, we obtained the material parameters for the two groups. The difference in the parameters between the two groups is attributed to the difference in the cavity temperatures used for epitaxial growth. Finally, we calculated the dark count probability of the two groups and validated the effectiveness of our method by comparing the calculated and experimental values. The evaluation method contributes to continuous improvements in the material quality of SPADs.