Abstract: An image sensor array includes a substrate and a plurality of pixels. Each pixel includes a single photon avalanche detector (SPAD), a quench device coupled to a respective SPAD and configured to quench an avalanche current, and time measurement circuitry configured to measure a time-of-flight of a photon. The SPAD has a trench coupled to the substrate and having a lattice mismatch with the substrate, and a substantially defect-free region coupled to the trench and configured to generate the avalanche current when the photon is detected in the defect-free region, wherein the trench and the defect-free region form an electrode. An imaging system includes an infrared laser configured to provide a pulse of light, and the image sensor array configured to receive the pulse from the infrared laser.

Abstract: A single photon avalanche (SPAD) device configured to detect visible to infrared light includes a substrate and a trench coupled to the substrate. The trench has a lattice mismatch with the substrate and has a height equal to or greater than its width. The device further includes a substantially defect-free semiconductor region that includes photosensitive material. The semiconductor region includes a well coupled to the trench and doped a first type. The well is configured to detect a photon and generate a current. The semiconductor region also includes a region formed in the well and doped a second type opposite to the first type. The well is configured to cause an avalanche multiplication of the current. The trench and the well form a first electrode and the region forms a second electrode.