Yanli Zhao
Single photon avalanche diodes (SPADs) are key enabling technologies for a wide range of applications. In the near-infrared region, In0.53Ga0.47As/InP (InGaAs/InP) SPADs are the primary candidates for practical applications requiring extremely weak light detection. Driven by the escalating demands for quantum communication and lidar, the performance of InGaAs/InP SPADs has been continuously enhanced and comprehensively investigated. It is necessary to make it clear that decreasing the excess noise of multiplication material also plays a non-negligible role in Geiger mode operation, the same as linear-mode telecommunication avalanche photodiodes (APDs), since it affects the avalanche breakdown probability and, hence, single photon detection efficiency. However, InP based SPAD usually has a lower dark count rate than those of Al based one. This can be attributed to that the material quality of binary InP is usually better than that of ternary alloy InAlAs (lower defect density). InAlAs or Sb based multiplication layers may have superior performances to those of InP based one due to their smaller k-factor. In this paper, we address the recent evolutions on InGaAs SPADs. In contrast with InP, low-noise multiplication materials, including In0.52Al0.48As (InAlAs) and Sb based semiconductors APDs, and their journey toward single-photon detection will be comprehensively reviewed.