Design and Simulation of a High-Responsivity Dielectric Metasurface Si-Based InGaAs Photodetector

A Si-based photodetector is the core device of Si-based optical interconnection; its material and performance are the key factors restricting its development. This paper conducts theoretical research on the issues of lattice mismatch between heterogeneous materials and low device responsivity in Si-based InGaAs photodetectors for the 1550 nm optical communication band. The material mismatch issue is addressed through the use of the high-aspect ratio trapping (ART) epitaxial technique, enabling the realization of high-performance Si-based III-V materials. By introducing a dielectric metasurface into the top layer of the structure, the light absorption efficiency is enhanced, realizing broadband optical absorption enhancement for Si-based photodetectors. This paper mainly focuses on designing the optimal parameters of the dielectric metasurface structure based on the finite-difference time-domain (FDTD) Solutions to achieve the performance analysis of a high-responsivity 1550 nm Si-based InGaAs photodetector. The results show that the quantum efficiency of the dielectric metasurface structure is theoretically estimated to be 88.8% and the response rate is 1.11 A/W, which is 2%~16% higher than that of the unetched structure in the whole band. The research results of this paper will provide new ideas for the development of novel, high-performance, and miniaturized Si-based photodetectors and lay a theoretical foundation for Si-based optical interconnection.