{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:26:07Z","timestamp":1760239567178,"version":"build-2065373602"},"reference-count":53,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2020,12,2]],"date-time":"2020-12-02T00:00:00Z","timestamp":1606867200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Two types of configurations are theoretically proposed to achieve high responsivity polarization-insensitive waveguide Schottky photodetectors, i.e., a dual-layer structure for 1.55 \u00b5m and a single-layer structure for 2 \u00b5m wavelength band. Mode hybridization effects between quasi-TM modes and sab1 modes in plasmonic waveguides are first presented and further investigated under diverse metal types with different thicknesses in this work. By utilizing the mode hybridization effects between quasi-TE mode and aab0 mode, and also quasi-TM and sab1 mode in our proposed hybrid plasmonic waveguide, light absorption enhancement can be achieved under both TE and TM incidence within ultrathin and short metal stripes, thus resulting in a considerable responsivity for Si-based sub-bandgap photodetection. For 1.55 \u00b5m wavelength, the Au-6 nm-thick device can achieve absorptance of 99.6%\/87.6% and responsivity of 138 mA\u00b7W\u22121\/121.2 mA\u00b7W\u22121 under TE\/TM incidence. Meanwhile, the Au-5 nm-thick device can achieve absorptance of 98.4%\/90.2% and responsivity of 89 mA\u00b7W\u22121\/81.7 mA\u00b7W\u22121 under TE\/TM incidence in 2 \u00b5m wavelength band. The ultra-compact polarization-insensitive waveguide Schottky photodetectors may have promising applications in large scale all-Si photonic integrated circuits for high-speed optical communication.<\/jats:p>","DOI":"10.3390\/s20236885","type":"journal-article","created":{"date-parts":[[2020,12,2]],"date-time":"2020-12-02T07:49:54Z","timestamp":1606895394000},"page":"6885","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Polarization-Insensitive Waveguide Schottky Photodetectors Based on Mode Hybridization Effects in Asymmetric Plasmonic Waveguides"],"prefix":"10.3390","volume":"20","author":[{"given":"Qian","family":"Li","sequence":"first","affiliation":[{"name":"Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Junjie","family":"Tu","sequence":"additional","affiliation":[{"name":"Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yang","family":"Tian","sequence":"additional","affiliation":[{"name":"Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanli","family":"Zhao","sequence":"additional","affiliation":[{"name":"Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"28594","DOI":"10.1364\/OE.20.028594","article-title":"Waveguide based compact silicon Schottky photodetector with enhanced responsivity in the telecom spectral band","volume":"20","author":"Goykhman","year":"2012","journal-title":"Opt. Express"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"895","DOI":"10.1002\/lpor.201600065","article-title":"State of the art all silicon sub-bandgap photodetectors at telecom and datacom wavelengths","volume":"10","author":"Casalino","year":"2016","journal-title":"Laser Photonics Rev."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"741","DOI":"10.1364\/OPTICA.3.000741","article-title":"Silicon-plasmonic internal-photoemission detector for 40\u2009Gbit\/s data reception","volume":"3","author":"Muehlbrandt","year":"2016","journal-title":"Optica"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1364\/OPTICA.2.000335","article-title":"Plasmonic enhanced silicon pyramids for internal photoemission Schottky detectors in the near-infrared regime","volume":"2","author":"Desiatov","year":"2015","journal-title":"Optica"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1259","DOI":"10.1364\/OPTICA.4.001259","article-title":"Highly sensitive wavelength-scale amorphous hybrid plasmonic detectors","volume":"4","author":"Su","year":"2017","journal-title":"Optica"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"17223","DOI":"10.1021\/acsomega.9b01705","article-title":"CMOS-Compatible Titanium Nitride for On-Chip Plasmonic Schottky Photodetectors","volume":"4","author":"Gosciniak","year":"2019","journal-title":"ACS Omega"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1364\/OPTICA.379549","article-title":"Giant enhancement of silicon plasmonic shortwave infrared photodetection using nanoscale self-organized metallic films","volume":"7","author":"Frydendahl","year":"2020","journal-title":"Optica"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"957","DOI":"10.1021\/acsnano.5b06199","article-title":"Nonradiative Plasmon Decay and Hot Carrier Dynamics: Effects of Phonons, Surfaces, and Geometry","volume":"10","author":"Brown","year":"2016","journal-title":"ACS Nano"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1515\/nanoph-2019-0396","article-title":"Fundamental limits of hot carrier injection from metal in nanoplasmonics","volume":"9","author":"Khurgin","year":"2020","journal-title":"Nanophotonics"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1564","DOI":"10.1109\/T-ED.1985.22165","article-title":"160 \u00d7 244 Element PtSi Schottky-barrier IRCCD image sensor","volume":"32","author":"Kosonocky","year":"1985","journal-title":"IEEE Trans. Electron. Dev."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1209","DOI":"10.1016\/0038-1101(71)90109-2","article-title":"Current transport in metal-semiconductor-metal (MSM) structures","volume":"14","author":"Sze","year":"1971","journal-title":"Solid State Electron."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1687","DOI":"10.1021\/nl400196z","article-title":"Embedding plasmonic nanostructure diodes enhances hot electron emission","volume":"13","author":"Knight","year":"2013","journal-title":"Nano Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1419","DOI":"10.1063\/1.103453","article-title":"Infrared response from metallic particles embedded in a single-crystal Si matrix: The layered internal photoemission sensor","volume":"57","author":"Fathauer","year":"1990","journal-title":"Appl. Phys. Lett."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"4030","DOI":"10.1021\/acsphotonics.8b00643","article-title":"The role of surface roughness in plasmonic-assisted internal photoemission schottky photodetectors","volume":"5","author":"Grajower","year":"2018","journal-title":"ACS Photonics"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"10955","DOI":"10.1021\/acsnano.7b04792","article-title":"Vertically illuminated, resonant cavity enhanced, graphene\u2013silicon Schottky photodetectors","volume":"11","author":"Casalino","year":"2017","journal-title":"ACS Nano"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1766","DOI":"10.1109\/JLT.2018.2791720","article-title":"Design of Resonant Cavity-Enhanced Schottky Graphene\/Silicon Photodetectors at 1550 nm","volume":"36","author":"Casalino","year":"2018","journal-title":"J. Lightwave Technol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4577","DOI":"10.1021\/acsphotonics.8b01037","article-title":"Free-Space Schottky Graphene\/Silicon Photodetectors Operating at 2 \u03bcm","volume":"5","author":"Casalino","year":"2018","journal-title":"ACS Photonics"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3005","DOI":"10.1021\/acs.nanolett.5b05216","article-title":"On-Chip Integrated, Silicon-Graphene Plasmonic Schottky Photodetector with High Responsivity and Avalanche Photogain","volume":"16","author":"Goykhman","year":"2016","journal-title":"Nano Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4758","DOI":"10.1021\/acsphotonics.8b01128","article-title":"Graphene photodetector integrated on a photonic crystal defect waveguide","volume":"5","author":"Schuler","year":"2018","journal-title":"ACS Photonics"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5066","DOI":"10.1364\/OL.42.005066","article-title":"Schottky graphene\/Si photodetector based on metal-dielectric hybrid hollow-core photonic crystal fibers","volume":"42","author":"Hosseinifar","year":"2017","journal-title":"Opt. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"7440","DOI":"10.1021\/acs.nanolett.5b02866","article-title":"Hot electron-based near-infrared photodetection using bilayer MoS2","volume":"15","author":"Wang","year":"2015","journal-title":"Nano Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"985","DOI":"10.1021\/acs.nanolett.6b04332","article-title":"Three-dimensional integration of black phosphorus photodetector with silicon photonics and nanoplasmonics","volume":"17","author":"Chen","year":"2017","journal-title":"Nano Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1900032.1","DOI":"10.1002\/lpor.201900032","article-title":"High-speed and high-responsivity hybrid silicon\/black-phosphorus waveguide photodetectors at 2 \u00b5m","volume":"13","author":"Yin","year":"2019","journal-title":"Laser Photonics Rev."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1109\/JQE.2010.2046720","article-title":"Thin-Film Schottky Barrier Photodetector Models","volume":"46","author":"Scales","year":"2010","journal-title":"IEEE J. Quantum Electron."},{"key":"ref_25","first-page":"569","article-title":"Theory and Measurements of Photoresponse for Thin Film Pd2Si and PtSi Infrared schottky Barrier Detectors with Optical Cavity","volume":"143","author":"Elabd","year":"1982","journal-title":"RCA Rev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"013902","DOI":"10.1063\/1.4973644","article-title":"Schottky hot-electron photodetector by cavity-enhanced optical Tamm resonance","volume":"110","author":"Li","year":"2017","journal-title":"Appl. Phys. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"10323","DOI":"10.1039\/C6NR01822J","article-title":"Planar microcavity-integrated hot-electron photodetector","volume":"8","author":"Zhang","year":"2016","journal-title":"Nanoscale"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1396","DOI":"10.1039\/C8NR05369C","article-title":"Planar dual-cavity hot-electron photodetectors","volume":"11","author":"Shao","year":"2019","journal-title":"Nanoscale"},{"key":"ref_29","first-page":"3266","article-title":"Cavity Enhanced Internal Photoemission Effect in Silicon Photodiode for Sub-Bandgap Detection","volume":"28","author":"Casalino","year":"2010","journal-title":"J. Lightwave Technol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"12599","DOI":"10.1364\/OE.20.012599","article-title":"Critically coupled silicon Fabry-Perot photodetectors based on the internal photoemission effect at 1550 nm","volume":"20","author":"Casalino","year":"2012","journal-title":"Opt. Express"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3288","DOI":"10.1038\/ncomms4288","article-title":"Silicon-based broadband antenna for high responsivity and polarization- insensitive photodetection at telecommunication wavelengths","volume":"5","author":"Lin","year":"2014","journal-title":"Nat. Commun."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3325","DOI":"10.1364\/OL.43.003325","article-title":"Polarization-insensitive hot-electron infrared photodetection by double Schottky junction and multilayer grating","volume":"43","author":"Zhang","year":"2018","journal-title":"Opt. Lett."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1643","DOI":"10.1038\/ncomms2642","article-title":"Narrowband photodetection in the near-infrared with a plasmon-induced hot electron device","volume":"4","author":"Sobhani","year":"2013","journal-title":"Nat. Commun."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"4925","DOI":"10.1364\/OL.37.004925","article-title":"Internal photoemission-based photodetector on Si microring resonator","volume":"37","author":"Zali","year":"2012","journal-title":"Opt. Lett."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1363","DOI":"10.1109\/LPT.2016.2543602","article-title":"Si-Schottky photodetector based on metal stripe in slot-waveguide microring resonator","volume":"28","author":"Hosseinifar","year":"2016","journal-title":"IEEE Photon. Technol. Lett."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.optcom.2017.03.071","article-title":"Design and optimization of high-performance slot-microring Si photodetector based on internal photoemission effect","volume":"397","author":"Hosseinifar","year":"2017","journal-title":"Opt. Commun."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1364\/OL.35.000529","article-title":"Surface-plasmon Schottky contact detector based on a symmetric metal stripe in silicon","volume":"35","author":"Scales","year":"2010","journal-title":"Opt. Lett."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1852","DOI":"10.1109\/JLT.2011.2147279","article-title":"Infrared Performance of Symmetric Surface-Plasmon Waveguide Schottky Detectors in Si","volume":"29","author":"Scales","year":"2011","journal-title":"J. Lightwave Technol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"4600209","DOI":"10.1109\/JSTQE.2012.2213585","article-title":"Subbandgap Asymmetric Surface Plasmon Waveguide Schottky Detectors on Silicon","volume":"19","author":"Akbari","year":"2013","journal-title":"IEEE J. Sel. Top. Quantum Electron."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"125417","DOI":"10.1103\/PhysRevB.63.125417","article-title":"Plasmon-polariton waves guided by thin lossy metal films of finite width: Bound modes of asymmetric structures","volume":"63","author":"Berini","year":"2001","journal-title":"Phys. Rev. B"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"10057","DOI":"10.1364\/OE.25.010057","article-title":"Enhanced light absorption in waveguide Schottky photodetector integrated with ultrathin metal\/silicide stripe","volume":"25","author":"Guo","year":"2017","journal-title":"Opt. Express"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"16413","DOI":"10.1364\/OE.27.016413","article-title":"Ultra-compact silicon waveguide-integrated Schottky photodetectors using perfect absorption from tapered metal nanobrick arrays","volume":"27","author":"Kwon","year":"2019","journal-title":"Opt. Express"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"2950","DOI":"10.1021\/acs.nanolett.9b04612","article-title":"Monolithic Plasmonic Waveguide Architecture for Passive and Active Optical Circuits","volume":"20","author":"Lin","year":"2020","journal-title":"Nano Lett."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"125010","DOI":"10.1088\/2040-8978\/17\/12\/125010","article-title":"Proposal of a broadband, polarization-insensitive and high-efficiency hot-carrier schottky photodetector integrated with a plasmonic silicon ridge waveguide","volume":"17","author":"Yang","year":"2015","journal-title":"J. Opt."},{"key":"ref_45","unstructured":"Yang, L., Kou, P., Shen, J., Lee, E.H., and He, S. (2013). A Polarization-insensitive and high-efficiency Schottky Photodetector integrated with a silicon ridge waveguide. arXiv."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1585","DOI":"10.1109\/LPT.2003.818683","article-title":"Effective dark current suppression with asymmetric MSM photodetectors in group IV semiconductors","volume":"15","author":"Chui","year":"2003","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_47","unstructured":"(2020, November 27). Lumerical. Available online: https:\/\/www.lumerical.com\/cn\/."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"13425","DOI":"10.1364\/OE.20.013425","article-title":"Mode conversion in tapered submicron silicon ridge optical waveguides","volume":"20","author":"Dai","year":"2012","journal-title":"Opt. Express"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"32452","DOI":"10.1364\/OE.23.032452","article-title":"Mode hybridization and conversion in silicon-on-insulator nanowires with angled sidewalls","volume":"23","author":"Dai","year":"2015","journal-title":"Opt. Express"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"10940","DOI":"10.1364\/OE.19.010940","article-title":"Novel concept for ultracompact polarization splitter-rotator based on silicon nanowires","volume":"19","author":"Dai","year":"2011","journal-title":"Opt. Express"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"25049","DOI":"10.1021\/acsami.7b07181","article-title":"High-quality ultrathin gold layers with an aptms adhesion for optimal performance of surface plasmon polariton-based devices","volume":"9","author":"Sukham","year":"2017","journal-title":"ACS Appl Mater. Interfaces"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1900196","DOI":"10.1002\/admi.201900196","article-title":"Ultrathin and ultrasmooth gold films on monolayer MoS2","volume":"6","author":"Yakubovsky","year":"2019","journal-title":"Adv. Mater. Interfaces"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"026103","DOI":"10.1063\/1.4973537","article-title":"Plasmonic silicon Schottky photodetectors: The physics behind graphene enhanced internal photoemission","volume":"2","author":"Levy","year":"2017","journal-title":"APL Photonics"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/23\/6885\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:40:30Z","timestamp":1760179230000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/23\/6885"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12,2]]},"references-count":53,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2020,12]]}},"alternative-id":["s20236885"],"URL":"https:\/\/doi.org\/10.3390\/s20236885","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2020,12,2]]}}}