| dc.description.abstract | Recently, since the application needs from remote sensing, three-dimensional imaging to information and financial security grows rapidly, the development of highly sensitive detectors receives much research interest. Among those detectors, single-photon avalanche diodes (SPAD) capable of detecting single photon due to their infinite gain become the most potential receivers for the applications of light detection and ranging (LiDAR), photonic quantum communication and quantum computing. The SPAD based on III-V compound semiconductors that can detect near infrared light including the fiber communication bands can be found their applications in LiDAR with eye-safety and improved ranging distance. Furthermore, the sensor exhibiting photon number resolving capability can also facilitate the application and development of photonic quantum science.
This work aims to develop a high performance SPAD and finally carry out a focal plane array. We bring a novel structure design to the SPAD by introducing a three stepwise electric field distribution to the multiplication layer, which helps to reduce the tunneling effect, improve timing characteristics and reduce the afterpulsing effect induced by the defects. As compared with planar-type, mesa-type is simpler to fabricate and has higher uniformity. Thus, We have fabricated a 4X4 mesa-type SPAD array and studied the yield and uniformity of each SPAD pixels. The results show that our SPAD has high uniformity from pixel to pixel, whose breakdown voltage and breakdown current is respectively 43.1± 0.1 V and20.8± 3.7 nA. As compared with the literature, the dark count rate is reduced by at most one order of magnitude. At the temperature of 250 K, the SPDE of 50% and the crosstalk probability of 8.43 % are obtained. In the future, enlarging the pixel cluster is envisioned due to the high pixel uniformity in the array, which could elevate the single photon detection efficiency. After integrating with a read-out IC, a hybrid SPAD image sensor can be used for the application of LiDAR and is possible to further perform photon number resolving by the spatial multiplexing scheme. | en_US |