All-optical broadband terahertz modulator based on NiO/Si heterojunction and interface photoconductivity analysis
All-optical THz heterojunction modulators have gained significant attention to meet the demanding requirements of next-generation wireless communication technologies. Self-powered heterojunction photodetectors have the high separation and utilization of photoinduced charge carriers even without exte...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2025-03-01
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| Series: | APL Materials |
| Online Access: | http://dx.doi.org/10.1063/5.0254193 |
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| author | Minjie Zhou Ao Li Shuhan Li Fan Zhang Zhiqiang Li Bing Jin |
| author_facet | Minjie Zhou Ao Li Shuhan Li Fan Zhang Zhiqiang Li Bing Jin |
| author_sort | Minjie Zhou |
| collection | DOAJ |
| description | All-optical THz heterojunction modulators have gained significant attention to meet the demanding requirements of next-generation wireless communication technologies. Self-powered heterojunction photodetectors have the high separation and utilization of photoinduced charge carriers even without external power sources. This high efficiency separation is attributed to the built-in electric field between heterojunction layers, a crucial factor for all-optical THz heterojunction modulators. Consequently, NiO/Si heterojunctions are anticipated to function as high-performance all-optical THz modulators. In this work, NiO/Si heterojunctions were fabricated, and their modulation properties were characterized using THz-time-domain spectroscopy (THz-TDS). The results demonstrate that the NiO/Si heterojunction exhibits broadband modulation (0.4–1.6 THz) with a high modulation depth of 85% (at 2 W/cm2 of 532 nm laser irradiation), representing a three-fold enhancement compared to bare silicon. Simple optical switching experiments further underscore the potential of these modulators for encoding information onto THz transmission waves. The modulation mechanism was elucidated through band theory and photoconductivity measurements. The photoinduced carrier mobility was estimated to be as high as 8285 cm2/(V s) under 532 nm laser irradiation, surpassing the values of other typical high-carrier-mobility materials. The results suggest that core heterojunction materials of self-powered photodetectors can serve as a promising foundation for high-performance all-optical THz modulators. In addition, THz-TDS emerges as a sensitive and non-contact technique for evaluating the performance of photodetectors. |
| format | Article |
| id | doaj-art-e2a665e187ea4a98834d2ea745f5b85e |
| institution | DOAJ |
| issn | 2166-532X |
| language | English |
| publishDate | 2025-03-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | APL Materials |
| spelling | doaj-art-e2a665e187ea4a98834d2ea745f5b85e2025-08-20T03:03:07ZengAIP Publishing LLCAPL Materials2166-532X2025-03-01133031119031119-1210.1063/5.0254193All-optical broadband terahertz modulator based on NiO/Si heterojunction and interface photoconductivity analysisMinjie Zhou0Ao Li1Shuhan Li2Fan Zhang3Zhiqiang Li4Bing Jin5Center for Optics and Research Engineer, Key Laboratory of Laser and Infrared System, Ministry of Education, Shandong University, Qingdao 266237, ChinaCenter for Optics and Research Engineer, Key Laboratory of Laser and Infrared System, Ministry of Education, Shandong University, Qingdao 266237, ChinaInstitute of Frontier Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Qingdao 266237, ChinaCenter for Optics and Research Engineer, Key Laboratory of Laser and Infrared System, Ministry of Education, Shandong University, Qingdao 266237, ChinaCenter for Optics and Research Engineer, Key Laboratory of Laser and Infrared System, Ministry of Education, Shandong University, Qingdao 266237, ChinaCenter for Optics and Research Engineer, Key Laboratory of Laser and Infrared System, Ministry of Education, Shandong University, Qingdao 266237, ChinaAll-optical THz heterojunction modulators have gained significant attention to meet the demanding requirements of next-generation wireless communication technologies. Self-powered heterojunction photodetectors have the high separation and utilization of photoinduced charge carriers even without external power sources. This high efficiency separation is attributed to the built-in electric field between heterojunction layers, a crucial factor for all-optical THz heterojunction modulators. Consequently, NiO/Si heterojunctions are anticipated to function as high-performance all-optical THz modulators. In this work, NiO/Si heterojunctions were fabricated, and their modulation properties were characterized using THz-time-domain spectroscopy (THz-TDS). The results demonstrate that the NiO/Si heterojunction exhibits broadband modulation (0.4–1.6 THz) with a high modulation depth of 85% (at 2 W/cm2 of 532 nm laser irradiation), representing a three-fold enhancement compared to bare silicon. Simple optical switching experiments further underscore the potential of these modulators for encoding information onto THz transmission waves. The modulation mechanism was elucidated through band theory and photoconductivity measurements. The photoinduced carrier mobility was estimated to be as high as 8285 cm2/(V s) under 532 nm laser irradiation, surpassing the values of other typical high-carrier-mobility materials. The results suggest that core heterojunction materials of self-powered photodetectors can serve as a promising foundation for high-performance all-optical THz modulators. In addition, THz-TDS emerges as a sensitive and non-contact technique for evaluating the performance of photodetectors.http://dx.doi.org/10.1063/5.0254193 |
| spellingShingle | Minjie Zhou Ao Li Shuhan Li Fan Zhang Zhiqiang Li Bing Jin All-optical broadband terahertz modulator based on NiO/Si heterojunction and interface photoconductivity analysis APL Materials |
| title | All-optical broadband terahertz modulator based on NiO/Si heterojunction and interface photoconductivity analysis |
| title_full | All-optical broadband terahertz modulator based on NiO/Si heterojunction and interface photoconductivity analysis |
| title_fullStr | All-optical broadband terahertz modulator based on NiO/Si heterojunction and interface photoconductivity analysis |
| title_full_unstemmed | All-optical broadband terahertz modulator based on NiO/Si heterojunction and interface photoconductivity analysis |
| title_short | All-optical broadband terahertz modulator based on NiO/Si heterojunction and interface photoconductivity analysis |
| title_sort | all optical broadband terahertz modulator based on nio si heterojunction and interface photoconductivity analysis |
| url | http://dx.doi.org/10.1063/5.0254193 |
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