Dynamic Modulation of THz Absorption Frequency, Bandwidth, and Amplitude via Strontium Titanate and Graphene
A multi-functional broadband absorber based on graphene and strontium titanate (STO) film was designed. Additionally, the frequency, bandwidth, and amplitude of the absorber could be tuned by adjusting temperature and Fermi level of the graphene. By using the finite-difference time-domain (FDTD) met...
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MDPI AG
2022-04-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/12/8/1353 |
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| author | Tong Wu Guan Wang Yang Jia Yabin Shao Yang Gao Yachen Gao |
| author_facet | Tong Wu Guan Wang Yang Jia Yabin Shao Yang Gao Yachen Gao |
| author_sort | Tong Wu |
| collection | DOAJ |
| description | A multi-functional broadband absorber based on graphene and strontium titanate (STO) film was designed. Additionally, the frequency, bandwidth, and amplitude of the absorber could be tuned by adjusting temperature and Fermi level of the graphene. By using the finite-difference time-domain (FDTD) method, the numerical calculation result shows that, when keeping the device temperature at 230 K and setting graphene Fermi level to be 1 eV, three absorption peaks at 1.72 THz, 2.08 THz, and 2.59 THz were realized and combined into a broadband absorption from 1.68 to 2.74 THz. As the STO temperature was increased from 230 K to 310 K, the center frequency moved from 2.2 THz to 2.45 THz; correspondingly, the broadband absorption range was widened from 1.06 THz to 1.24 THz. When the temperature was fixed at 230 K and the graphene Fermi level was tuned from 1 eV to 0.7 eV, the absorption bandwidth decreased from 1.06 THz to 0.64 THz. While the Fermi level was tuned continually to be 0.01 eV, only a single absorption peak with an absorption rate of 0.29 existed. The broadband absorption and tuning mechanism of the absorber were analyzed using impedance matching theory. Furthermore, we also studied the effect of incident angle and polarization direction on the properties of the absorber. The multi-functional tunable absorber provides potential applications for the design of more efficient terahertz functional devices in the future. |
| first_indexed | 2024-03-09T10:31:29Z |
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| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-09T10:31:29Z |
| publishDate | 2022-04-01 |
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| spelling | doaj.art-c448ffe9265f42a0aff7de7cffb8b0d52023-12-01T21:16:59ZengMDPI AGNanomaterials2079-49912022-04-01128135310.3390/nano12081353Dynamic Modulation of THz Absorption Frequency, Bandwidth, and Amplitude via Strontium Titanate and GrapheneTong Wu0Guan Wang1Yang Jia2Yabin Shao3Yang Gao4Yachen Gao5Department of Optoelectronic Information, Electronic Engineering College, Heilongjiang University, Harbin 150080, ChinaDepartment of Optoelectronic Information, Electronic Engineering College, Heilongjiang University, Harbin 150080, ChinaDepartment of Optoelectronic Information, Electronic Engineering College, Heilongjiang University, Harbin 150080, ChinaSchool of Jia Yang, Zhejiang Shuren University, Shaoxing 312028, ChinaDepartment of Optoelectronic Information, Electronic Engineering College, Heilongjiang University, Harbin 150080, ChinaDepartment of Optoelectronic Information, Electronic Engineering College, Heilongjiang University, Harbin 150080, ChinaA multi-functional broadband absorber based on graphene and strontium titanate (STO) film was designed. Additionally, the frequency, bandwidth, and amplitude of the absorber could be tuned by adjusting temperature and Fermi level of the graphene. By using the finite-difference time-domain (FDTD) method, the numerical calculation result shows that, when keeping the device temperature at 230 K and setting graphene Fermi level to be 1 eV, three absorption peaks at 1.72 THz, 2.08 THz, and 2.59 THz were realized and combined into a broadband absorption from 1.68 to 2.74 THz. As the STO temperature was increased from 230 K to 310 K, the center frequency moved from 2.2 THz to 2.45 THz; correspondingly, the broadband absorption range was widened from 1.06 THz to 1.24 THz. When the temperature was fixed at 230 K and the graphene Fermi level was tuned from 1 eV to 0.7 eV, the absorption bandwidth decreased from 1.06 THz to 0.64 THz. While the Fermi level was tuned continually to be 0.01 eV, only a single absorption peak with an absorption rate of 0.29 existed. The broadband absorption and tuning mechanism of the absorber were analyzed using impedance matching theory. Furthermore, we also studied the effect of incident angle and polarization direction on the properties of the absorber. The multi-functional tunable absorber provides potential applications for the design of more efficient terahertz functional devices in the future.https://www.mdpi.com/2079-4991/12/8/1353terahertzmulti-functionalabsorberbroadband absorption |
| spellingShingle | Tong Wu Guan Wang Yang Jia Yabin Shao Yang Gao Yachen Gao Dynamic Modulation of THz Absorption Frequency, Bandwidth, and Amplitude via Strontium Titanate and Graphene Nanomaterials terahertz multi-functional absorber broadband absorption |
| title | Dynamic Modulation of THz Absorption Frequency, Bandwidth, and Amplitude via Strontium Titanate and Graphene |
| title_full | Dynamic Modulation of THz Absorption Frequency, Bandwidth, and Amplitude via Strontium Titanate and Graphene |
| title_fullStr | Dynamic Modulation of THz Absorption Frequency, Bandwidth, and Amplitude via Strontium Titanate and Graphene |
| title_full_unstemmed | Dynamic Modulation of THz Absorption Frequency, Bandwidth, and Amplitude via Strontium Titanate and Graphene |
| title_short | Dynamic Modulation of THz Absorption Frequency, Bandwidth, and Amplitude via Strontium Titanate and Graphene |
| title_sort | dynamic modulation of thz absorption frequency bandwidth and amplitude via strontium titanate and graphene |
| topic | terahertz multi-functional absorber broadband absorption |
| url | https://www.mdpi.com/2079-4991/12/8/1353 |
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