Planar semiconductor InGaAs/InP single photon avalanche diodes with high responsivity and low dark count rate are preferred single photon detectors in near-infrared communication. However, even with well-designed structures and well-controlled operational conditions, the performance of InGaAs/InP SPADs is limited by the inherent characteristics of avalanche process and the growth quality of InGaAs/InP materials. It is difficult to ensure high detection efficiency while the dark count rate is controlled within a certain range at present. In this paper, we fabricated a device with a thick InGaAs absorption region and an anti-reflection layer. The quantum efficiency of this device reaches 83.2%. We characterized the single-photon performance of the device by a quenching circuit consisting of parallel-balanced InGaAs/InP single photon detectors and single-period sinusoidal pulse gating. The spike pulse caused by the capacitance effect of the device is eliminated by using the characteristics of parallel balanced common mode signal elimination, and the detection of small avalanche pulse amplitude signal is realized. The maximum detection efficiency is 55.4% with a dark count rate of 43.8 kHz and a noise equivalent power of 6.96 × 10−17 W/Hz1/2 at 247 K. Compared with other reported detectors, this SPAD exhibits higher SPDE and lower noise-equivalent power at a higher cooling temperature.

Planar InGaAs/InP avalanche photo diodes (APDs) are preferred single photon-detectors in the near-infrared region. They are usually fabricated using the double-diffusion method to avoid edge breakdown. However, this effect cannot be avoided completely as the bias voltage increases in the Geiger mode(GM). In this study, the influence of the deep diffusion window diameter on the premature edge breakdown of GM APDs was quantitatively analyzed using optical probe scanning method. Both numerical simulations and experimental measurements were performed. The electric field and dark current distribution, and the photon current under different optical input positions were numerically simulated. APDs with different deep diffusion window diameters were fabricated and tested to measure the photon current response. According to the normalized scanning photo current, we find that premature edge breakdown diminishes as the diffusion diameter of the device decreases. The position of the maximum electric field gradually shifted to the center as the diameter of the device decreased, and this shift gradually increased as the diameter decreased. The influence of edge breakdown was found to be avoided on the APD with a diameter of 10μm, indicated by the avalanche gain reaching the maximum at the center, and the overlapping of optical and maximum electric gain regions is realized, which is crucial for high detection efficiency and low dark count of single photon detection.