{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,2,21]],"date-time":"2025-02-21T14:51:44Z","timestamp":1740149504360,"version":"3.37.3"},"reference-count":54,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,5,24]],"date-time":"2022-05-24T00:00:00Z","timestamp":1653350400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Young Scholar Fellowship Programby Ministry of Science and Technology (MOST) Taiwan","award":["MOST 110\u20132636\u2013E\u2013194\u2013002"]},{"name":"Air Force Office of Scientific Research","award":["FA9550\u201319\u20131\u20130341","FA9550\u201321\u20131\u20130347"]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"Silicon photonics is emerging as a competitive platform for electronic\u2013photonic integrated circuits (EPICs) in the 2 \u00b5m wavelength band where GeSn photodetectors (PDs) have proven to be efficient PDs. In this paper, we present a comprehensive theoretical study of GeSn vertical p\u2013i\u2013n homojunction waveguide photodetectors (WGPDs) that have a strain-free and defect-free GeSn active layer for 2 \u00b5m Si-based EPICs. The use of a narrow-gap GeSn alloy as the active layer can fully cover entire the 2 \u00b5m wavelength band. The waveguide structure allows for decoupling the photon-absorbing path and the carrier collection path, thereby allowing for the simultaneous achievement of high-responsivity and high-bandwidth (BW) operation at the 2 \u00b5m wavelength band. We present the theoretical models to calculate the carrier saturation velocities, optical absorption coefficient, responsivity, 3-dB bandwidth, zero-bias resistance, and detectivity, and optimize this device structure to achieve highest performance at the 2 \u00b5m wavelength band. The results indicate that the performance of the GeSn WGPD has a strong dependence on the Sn composition and geometric parameters. The optimally designed GeSn WGPD with a 10% Sn concentration can give responsivity of 1.55 A\/W, detectivity of 6.12 \u00d7 1010 cmHz\u00bdW\u22121 at 2 \u00b5m wavelength, and ~97 GHz BW. Therefore, this optimally designed GeSn WGPD is a potential candidate for silicon photonic EPICs offering high-speed optical communications.<\/jats:p>","DOI":"10.3390\/s22113978","type":"journal-article","created":{"date-parts":[[2022,5,25]],"date-time":"2022-05-25T04:14:14Z","timestamp":1653452054000},"page":"3978","source":"Crossref","is-referenced-by-count":16,"title":["Design and Optimization of GeSn Waveguide Photodetectors for 2-\u00b5m Band Silicon Photonics"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3233-004X","authenticated-orcid":false,"given":"Soumava","family":"Ghosh","sequence":"first","affiliation":[{"name":"Institute of Radio Physics and Electronics, University of Calcutta, Kolkata 700009, India"}]},{"given":"Radhika","family":"Bansal","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, and Advanced Institute of Manufacturing with High\u2013Tech Innovations (AIM\u2013HI), National Chung Cheng University, Chiayi County 62102, Taiwan"}]},{"given":"Greg","family":"Sun","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Massachusetts-Boston, Boston, MA 02125, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7303-7056","authenticated-orcid":false,"given":"Richard A.","family":"Soref","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Massachusetts-Boston, Boston, MA 02125, USA"}]},{"given":"Hung-Hsiang","family":"Cheng","sequence":"additional","affiliation":[{"name":"Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3739-5451","authenticated-orcid":false,"given":"Guo-En","family":"Chang","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, and Advanced Institute of Manufacturing with High\u2013Tech Innovations (AIM\u2013HI), National Chung Cheng University, Chiayi County 62102, Taiwan"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1109\/JLT.2009.2030693","article-title":"Approaching the non\u2013linear Shanon limit","volume":"28","author":"Ellis","year":"2010","journal-title":"J. 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