High-performance room temperature InP/InGaAs single-photon detector made by a single diffusion process

Traditional InP/InGaAs single-photon avalanche detectors require cooling to approximately 240 K to reduce dark counts, necessitating the use of semiconductor thermoelectric cooling, which increases both volume and power consumption. Through optimization of the material structure and fabrication processes via a single diffusion process, we have developed a high-performance 1550 nm single-photon detector that operates at room temperature (293 K). At a detection efficiency of 20.1%, the dark count rate achieved was 6.82 kHz, with an afterpulse probability of 0.15% and a timing jitter of 120 ps under gated operation. This is the lowest dark count rate reported to date for a 1550 nm single-photon detector operating at room temperature. Furthermore, in a purely passive quenching mode, we obtained a dark count rate of 32.6 kHz with a detection efficiency of 10.3% at room temperature by integrating a SiO2/Cr film resistor through a sputtering process into the detector. Our scheme provides an alternative choice for room-temperature single-photon detectors and should significantly advance their application in compact, low-power devices.