Photoresponse of Graphene Channel in Graphene-Oxide–Silicon Photodetectors
Graphene-on-silicon photodetectors exhibit broadband detection capabilities with high responsivities, surpassing those of their counterpart semiconductors fabricated purely using graphene or Si. In these studies, graphene channels were considered electrically neutral, and signal amplification was ty...
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MDPI AG
2023-05-01
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Online Access: | https://www.mdpi.com/2304-6732/10/5/568 |
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author | Kuo-Chih Lee Yu-Hsien Chuang Chen-Kai Huang Hui Li Guo-En Chang Kuan-Ming Hung Hung Hsiang Cheng |
author_facet | Kuo-Chih Lee Yu-Hsien Chuang Chen-Kai Huang Hui Li Guo-En Chang Kuan-Ming Hung Hung Hsiang Cheng |
author_sort | Kuo-Chih Lee |
collection | DOAJ |
description | Graphene-on-silicon photodetectors exhibit broadband detection capabilities with high responsivities, surpassing those of their counterpart semiconductors fabricated purely using graphene or Si. In these studies, graphene channels were considered electrically neutral, and signal amplification was typically attributed to the photogating effect. By contrast, herein, we show graphene channels to exhibit p-type characteristics using a structure wherein a thin oxide layer insulated the graphene from Si. The p-type carrier concentration is higher (six-times) than the photoaging-induced carrier concentration and dominates the photocurrent. Additionally, we demonstrate photocurrent tunability in the channel. By operating this device under a back-gated bias, photocurrent tuning is realized with not only amplification but also attenuation. Gate amplification produces a current equal to the photogating current at a low bias (0.2 V), and it is approximately two orders of magnitude larger at a bias of 2 V, indicating the operation effectiveness. Meanwhile, photocurrent attenuation enables adjustments in the detector output for compatibility with read-out circuits. A quantification model of gate-dependent currents is further established based on the simulation model used for metal–oxide–semiconductor devices. Thus, this study addresses fundamental issues concerning graphene channels and highlights the potential of such devices as gate-tunable photodetectors in high-performance optoelectronics. |
first_indexed | 2024-03-11T03:23:43Z |
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id | doaj.art-bd24661721b94bdaadc3d8fa5f4628f2 |
institution | Directory Open Access Journal |
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language | English |
last_indexed | 2024-03-11T03:23:43Z |
publishDate | 2023-05-01 |
publisher | MDPI AG |
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series | Photonics |
spelling | doaj.art-bd24661721b94bdaadc3d8fa5f4628f22023-11-18T02:54:36ZengMDPI AGPhotonics2304-67322023-05-0110556810.3390/photonics10050568Photoresponse of Graphene Channel in Graphene-Oxide–Silicon PhotodetectorsKuo-Chih Lee0Yu-Hsien Chuang1Chen-Kai Huang2Hui Li3Guo-En Chang4Kuan-Ming Hung5Hung Hsiang Cheng6Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 106, TaiwanGraduate School of Advanced Technology Program for Semiconductor Devices, Materials, and Hetero-Integration, National Taiwan University, Taipei 106, TaiwanCenter for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 106, TaiwanCenter for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 106, TaiwanDepartment of Mechanical Engineering, and Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, Chiayi County 62102, TaiwanDepartment of Electronics Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 807, TaiwanCenter for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 106, TaiwanGraphene-on-silicon photodetectors exhibit broadband detection capabilities with high responsivities, surpassing those of their counterpart semiconductors fabricated purely using graphene or Si. In these studies, graphene channels were considered electrically neutral, and signal amplification was typically attributed to the photogating effect. By contrast, herein, we show graphene channels to exhibit p-type characteristics using a structure wherein a thin oxide layer insulated the graphene from Si. The p-type carrier concentration is higher (six-times) than the photoaging-induced carrier concentration and dominates the photocurrent. Additionally, we demonstrate photocurrent tunability in the channel. By operating this device under a back-gated bias, photocurrent tuning is realized with not only amplification but also attenuation. Gate amplification produces a current equal to the photogating current at a low bias (0.2 V), and it is approximately two orders of magnitude larger at a bias of 2 V, indicating the operation effectiveness. Meanwhile, photocurrent attenuation enables adjustments in the detector output for compatibility with read-out circuits. A quantification model of gate-dependent currents is further established based on the simulation model used for metal–oxide–semiconductor devices. Thus, this study addresses fundamental issues concerning graphene channels and highlights the potential of such devices as gate-tunable photodetectors in high-performance optoelectronics.https://www.mdpi.com/2304-6732/10/5/568graphenephotodetectorphotogating |
spellingShingle | Kuo-Chih Lee Yu-Hsien Chuang Chen-Kai Huang Hui Li Guo-En Chang Kuan-Ming Hung Hung Hsiang Cheng Photoresponse of Graphene Channel in Graphene-Oxide–Silicon Photodetectors Photonics graphene photodetector photogating |
title | Photoresponse of Graphene Channel in Graphene-Oxide–Silicon Photodetectors |
title_full | Photoresponse of Graphene Channel in Graphene-Oxide–Silicon Photodetectors |
title_fullStr | Photoresponse of Graphene Channel in Graphene-Oxide–Silicon Photodetectors |
title_full_unstemmed | Photoresponse of Graphene Channel in Graphene-Oxide–Silicon Photodetectors |
title_short | Photoresponse of Graphene Channel in Graphene-Oxide–Silicon Photodetectors |
title_sort | photoresponse of graphene channel in graphene oxide silicon photodetectors |
topic | graphene photodetector photogating |
url | https://www.mdpi.com/2304-6732/10/5/568 |
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