{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T17:48:52Z","timestamp":1770918532989,"version":"3.50.1"},"reference-count":35,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2024,5,24]],"date-time":"2024-05-24T00:00:00Z","timestamp":1716508800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Open Foundation of State Key Laboratory of Refractories and Metallurgy (Wuhan University of Science and Technology)","award":["G202302"],"award-info":[{"award-number":["G202302"]}]},{"name":"Open Foundation of State Key Laboratory of Refractories and Metallurgy (Wuhan University of Science and Technology)","award":["23KJA510005"],"award-info":[{"award-number":["23KJA510005"]}]},{"name":"Natural Science Foundation of Jiangsu Higher Education Institutions of China","award":["G202302"],"award-info":[{"award-number":["G202302"]}]},{"name":"Natural Science Foundation of Jiangsu Higher Education Institutions of China","award":["23KJA510005"],"award-info":[{"award-number":["23KJA510005"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The nonlinear characteristics of avalanche photodiodes (APDs) inhibit their performance in high-speed communication systems, thereby limiting their widespread application as optical detectors. Existing theoretical models have not fully elucidated complex phenomena encountered in actual device structures. In this study, actual APD structures exhibiting lower linearity than their ideal counterparts were revealed. Simulation analysis and physical inference based on GaN APDs reveal that electrode size is a noteworthy factor influencing response linearity. This discovery expands the nonlinear theory of APDs, suggesting that APD linearity can be enhanced by suppressing the electrode size effect. A physical model was developed to explain this phenomenon, which is attributed to charge accumulation at the edge of the contact layer. Therefore, we proposed an improved APD design that incorporates an additional gap layer and a buffer layer to stabilize the internal gain under high-current-density conditions, thereby enhancing linearity. Our improved APD design increases the linear threshold for optical input power by 4.46 times. This study not only refines the theoretical model for APD linearity but also opens new pathways for improving the linearity of high-speed optoelectronic detectors.<\/jats:p>","DOI":"10.3390\/s24113366","type":"journal-article","created":{"date-parts":[[2024,5,24]],"date-time":"2024-05-24T05:36:06Z","timestamp":1716528966000},"page":"3366","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Enhancing Linearity of Light Response in Avalanche Photodiodes by Suppressing Electrode Size Effect"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-0876-2068","authenticated-orcid":false,"given":"Hongyi","family":"Gan","sequence":"first","affiliation":[{"name":"College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Junwen","family":"Yu","sequence":"additional","affiliation":[{"name":"College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2365-3357","authenticated-orcid":false,"given":"Xiangfu","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China"},{"name":"The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,5,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"096101","DOI":"10.1117\/1.OE.60.9.096101","article-title":"Evaluation and experimental comparisons of different photodetector receivers for visible light communication systems under typical scenarios","volume":"60","author":"Mu","year":"2021","journal-title":"Opt. 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