Fig. 3. The waveguide-integrated Si/2DM PDs with metal-2DM-metal configurations.

a A graphene plasmonic PD working with the PV effect. b A plasmonically enhanced graphene PD working on the BOL effect. c A horizontally asymmetric graphene PD with one gate electrode based on the PTE effect. d A microring resonator-integrated two-gate graphene PD based on the PTE effect. e The Si-G hybrid plasmonic waveguide PDs operating at 1.55 and 2 μm. f A two-gate MoTe₂ PD operating at 1.16 μm based on the PV effect. g A strain-engineered MoTe₂ PD integrated on a microring resonator operating at 1.55 μm. h A PtSe₂ PD operating at 1.55 μm. i A black-phosphorus PD operating at 1.55 μm with 3 GHz bandwidth. j A black-phosphorus PD operating at 2 μm. k A PG effect-based black phosphorus PD operating at the wavelength band of 3.68–4.03 μm. Figures reproduced with permissions from: a ref. ¹⁰⁸, ^©2020 De Gruyter, Berlin/Boston, under Creative Commons Attribution 4.0 International license (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/); b ref. ¹¹⁹, ^©2018 American Chemical Society; c ref. ⁶⁰, ^©2015 American Chemical Society; d ref. ¹¹⁵, under Creative Commons Attribution 4.0 International license (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/); e ref. ⁵⁸, ^©2020 Springer Nature Limited, under Creative Commons Attribution 4.0 International license (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/); f ref. ^{64 ©}2017 Springer Nature Limited. g ref. ⁷⁰, ^©2020 Springer Nature Limited; h ref. ¹²¹, ^©2020 American Chemical Society; i ref. ⁷¹, ^©2015 Springer Nature Limited; j ref. ⁷², ^©2019 John Wiley & Sons, Inc. k ref. ⁶⁸, ^©2018 American Chemical Society. Further permissions related to the figures should be directed to the copyright holders.