Improved electrical parameter of graphene in Si/SiO2/Al2O3/graphene heterostructure for THz modulation
We proposed the extraction of necessary electrical parameters of graphene (Gr) on Si/SiO _2 /Gr and Si/SiO _2 /Al _2 O _3 /Gr heterostructure THz modulators using the THz measurement technique. The obtained average THz absorption is 24.5% more on Si/SiO _2 /Al _2 O _3 /Gr as compared to the Gr on Si...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2022-01-01
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| Series: | Materials Research Express |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/2053-1591/ac9e43 |
| Summary: | We proposed the extraction of necessary electrical parameters of graphene (Gr) on Si/SiO _2 /Gr and Si/SiO _2 /Al _2 O _3 /Gr heterostructure THz modulators using the THz measurement technique. The obtained average THz absorption is 24.5% more on Si/SiO _2 /Al _2 O _3 /Gr as compared to the Gr on Si/SiO _2 . The calculated value of the carrier mobility of graphene on Si/SiO _2 /Al _2 O _3 is 2.33 times more than that on Si/SiO _2 . The presence of Al _2 O _3 may play a role of a barrier for diffusion of trap and impurity charges from Si/SiO _2 to graphene which may lead to higher mobility and higher THz absorption. THz modulation measurements by optical pumping were also performed. Maximum modulation depth was 18.54% on Si/SiO _2 /Al _2 O _3 /Gr modulator at 2W pumping power which is 16.54% higher as compared to Gr on Si/SiO _2 . This shows that graphene on Si/SiO _2 /Al _2 O _3 heterostructure exhibits great potential for the development of an efficient electro-optical THz modulator as compared to Si/SiO _2 /Gr modulator. |
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| ISSN: | 2053-1591 |