Single photo detector epitaxial design and optimization

Abstract

This article uses semiconductor simulation software to simulate the composition concentration and thickness of the epitaxial structure of the InGaAsP near-infrared single photo avalanche detector. By optimizing and adjusting different parameters, this study manifests the ideal inner energy band, electrical field distribution, making the overall performance of the SPAD has been improved. The calculation results of I-V curve show that by controlling the thickness of the charge layer and multiplication layer within a certain range, the punch voltage and avalanche voltage of the device can be appropriately reduced to 25V and 72V, and the maximum multiplication factor can be obtained over 10000 under the avalanche voltage. By depicting the infrared spectrum response curve, it can be seen that in the range of 0.9 to 1.55um, the internal quantum efficiency of the SPAD is basically maintained above 70%, indicating that the device has a high photon conversion efficiency and meets the demand for single-photon detection.