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Subwavelength Terahertz Imaging of Graphene Photoconductivity.

ABSTRACT: Using a spatially structured, optical pump pulse with a terahertz (THz) probe pulse, we are able to determine spatial variations of the ultrafast THz photoconductivity with subwavelength resolution (75 ?m ? ?/5 at 0.8 THz) in a planar graphene sample. We compare our results to Raman spectroscopy and correlate the existence of the spatial inhomogeneities between the two measurements. We find a strong correlation with inhomogeneity in electron density. This demonstrates the importance of eliminating inhomogeneities in doping density during CVD growth and fabrication for photoconductive devices.

SUBMITTER: Hornett SM

PROVIDER: S-EPMC5115732 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature

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Subwavelength Terahertz Imaging of Graphene Photoconductivity.

Hornett Samuel M SM Stantchev Rayko I RI Vardaki Martha Z MZ Beckerleg Chris C Hendry Euan E

Nano letters 20161018 11

Using a spatially structured, optical pump pulse with a terahertz (THz) probe pulse, we are able to determine spatial variations of the ultrafast THz photoconductivity with subwavelength resolution (75 μm ≈ λ/5 at 0.8 THz) in a planar graphene sample. We compare our results to Raman spectroscopy and correlate the existence of the spatial inhomogeneities between the two measurements. We find a strong correlation with inhomogeneity in electron density. This demonstrates the importance of eliminati ...[more]

PMID: 27736073

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