Low-frequency noise in graphene tunnel junctions
Graphene tunnel junctions are a promising experimental platform for single molecule electronics and biosensing. Ultimately their noise properties will play a critical role in developing these applications. Here we report a study of electrical noise in graphene tunnel junctions fabricated through fee...
| Main Authors: | , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
American Chemical Society
2018
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| _version_ | 1797062867029065728 |
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| author | Puczkarski, P Wu, Q Sadeghi, H Hou, S Karimi, A Sheng, Y Warner, J Lambert, C Briggs, G Mol, J |
| author_facet | Puczkarski, P Wu, Q Sadeghi, H Hou, S Karimi, A Sheng, Y Warner, J Lambert, C Briggs, G Mol, J |
| author_sort | Puczkarski, P |
| collection | OXFORD |
| description | Graphene tunnel junctions are a promising experimental platform for single molecule electronics and biosensing. Ultimately their noise properties will play a critical role in developing these applications. Here we report a study of electrical noise in graphene tunnel junctions fabricated through feedback-controlled electroburning. We observe random telegraph signals characterized by a Lorentzian noise spectrum at cryogenic temperatures (77 K) and a 1/f noise spectrum at room temperature. To gain insight into the origin of these noise features, we introduce a theoretical model that couples a quantum mechanical tunnel barrier to one or more classical fluctuators. The fluctuators are identified as charge traps in the underlying dielectric, which through random fluctuations in their occupation introduce time-dependent modulations in the electrostatic environment that shift the potential barrier of the junction. Analysis of the experimental results and the tight-binding model indicate that the random trap occupation is governed by Poisson statistics. In the 35 devices measured at room temperature, we observe a 20–60% time-dependent variance of the current, which can be attributed to a relative potential barrier shift of between 6% and 10%. In 10 devices measured at 77 K, we observe a 10% time-dependent variance of the current, which can be attributed to a relative potential barrier shift of between 3% and 4%. Our measurements reveal a high sensitivity of the graphene tunnel junctions to their local electrostatic environment, with observable features of intertrap Coulomb interactions in the distribution of current switching amplitudes. |
| first_indexed | 2024-03-06T20:51:44Z |
| format | Journal article |
| id | oxford-uuid:37ce5f12-f4be-4a88-a915-479897a0aab5 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:51:44Z |
| publishDate | 2018 |
| publisher | American Chemical Society |
| record_format | dspace |
| spelling | oxford-uuid:37ce5f12-f4be-4a88-a915-479897a0aab52022-03-26T13:46:24ZLow-frequency noise in graphene tunnel junctionsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:37ce5f12-f4be-4a88-a915-479897a0aab5EnglishSymplectic Elements at OxfordAmerican Chemical Society2018Puczkarski, PWu, QSadeghi, HHou, SKarimi, ASheng, YWarner, JLambert, CBriggs, GMol, JGraphene tunnel junctions are a promising experimental platform for single molecule electronics and biosensing. Ultimately their noise properties will play a critical role in developing these applications. Here we report a study of electrical noise in graphene tunnel junctions fabricated through feedback-controlled electroburning. We observe random telegraph signals characterized by a Lorentzian noise spectrum at cryogenic temperatures (77 K) and a 1/f noise spectrum at room temperature. To gain insight into the origin of these noise features, we introduce a theoretical model that couples a quantum mechanical tunnel barrier to one or more classical fluctuators. The fluctuators are identified as charge traps in the underlying dielectric, which through random fluctuations in their occupation introduce time-dependent modulations in the electrostatic environment that shift the potential barrier of the junction. Analysis of the experimental results and the tight-binding model indicate that the random trap occupation is governed by Poisson statistics. In the 35 devices measured at room temperature, we observe a 20–60% time-dependent variance of the current, which can be attributed to a relative potential barrier shift of between 6% and 10%. In 10 devices measured at 77 K, we observe a 10% time-dependent variance of the current, which can be attributed to a relative potential barrier shift of between 3% and 4%. Our measurements reveal a high sensitivity of the graphene tunnel junctions to their local electrostatic environment, with observable features of intertrap Coulomb interactions in the distribution of current switching amplitudes. |
| spellingShingle | Puczkarski, P Wu, Q Sadeghi, H Hou, S Karimi, A Sheng, Y Warner, J Lambert, C Briggs, G Mol, J Low-frequency noise in graphene tunnel junctions |
| title | Low-frequency noise in graphene tunnel junctions |
| title_full | Low-frequency noise in graphene tunnel junctions |
| title_fullStr | Low-frequency noise in graphene tunnel junctions |
| title_full_unstemmed | Low-frequency noise in graphene tunnel junctions |
| title_short | Low-frequency noise in graphene tunnel junctions |
| title_sort | low frequency noise in graphene tunnel junctions |
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