Optimization of electrode distance and 2D material coverage for PdSe_(2)-based waveguide-integrated photodetectors  

作　　者：Tianxun GONG Beilin ZHU Luyu LV Zhengyi LIU Xiaosheng ZHANG 

机构地区：[1]School of Integrated Circuit Science and Engineering(Exemplary School of Microelectronics),University of Electronic Science and Technology of China,Chengdu,611731,China

出　　处：《Science China(Technological Sciences)》2025年第3期319-330,共12页中国科学(技术科学英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.61905035,62371095,62074029);the National Key Research and Development Program of China(Grant No.2022YFB3206100);the Natural Science Foundation of Sichuan Province(Grant Nos.2022NSFSC0652,2022JDTD0020)。

摘　　要：Silicon-based waveguide-integrated photodetectors,leveraging their distinct advantages,have become crucial components in integrated photonic circuits.Despite achieving combined designs of two-dimensional materials and silicon waveguides,understanding the underlying mechanisms and optimizing structural designs remains challenging.In this study,we systematically investigated the impact of electrode distances on the optical loss and photoelectric response of PdSe_(2)-based strip,rib,and slot waveguide-integrated photodetectors.Optimal electrode distances were determined,leading to significant enhancements in responsivity.Specifically,our devices demonstrated high responsivity values of 9.24 A/W(strip),3.34 A/W(rib),and 4.52 A/W(slot)at 1550 nm.These results represent remarkable enhancements of 481%,237%,and 267%,respectively,compared to the initial unoptimized electrode configurations.Additionally,we found the slot waveguide-integrated photodetector achieves 34%of absorption saturation with PdSe_(2)coverage of approximately 10μm,while the rib waveguide enables 70%absorption(not yet saturated)with PdSe_(2)coverage of 50μm.Furthermore,we explored the effect of input power on the performance of these photodetectors,finding that lower input optical power yields higher responsivity and external quantum efficiency(EQE),especially for slot waveguide-integrated photodetectors.Additionally,these detectors exhibit fast optical response rates across the optical communication O to U bands,with strip,rib and slot waveguide-integrated photodetectors demonstrating 3 dB bandwidths of 23.10,14.49,and 14.86 GHz,respectively.

关 键 词：silicon waveguide PHOTODETECTOR PdSe_(2) electrode distance RESPONSIVITY 

分 类 号：TN36[电子电信—物理电子学]