High-performance silicon-graphene hybrid plasmonic waveguide photodetectors beyond 1.55 {\mu}m
A fast silicon-graphene hybrid plasmonic waveguide photodetectors beyond 1.55 {\mu}m is proposed and realized by introducing an ultra-thin wide silicon-on-insulator ridge core region with a narrow metal cap. With this novel design, the light absorption in graphene is enhanced while the metal absorpt...
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Main Authors | , , , , , , , , , , , , , |
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Format | Journal Article |
Language | English |
Published |
18.07.2019
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Subjects | |
Online Access | Get full text |
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Summary: | A fast silicon-graphene hybrid plasmonic waveguide photodetectors beyond 1.55
{\mu}m is proposed and realized by introducing an ultra-thin wide
silicon-on-insulator ridge core region with a narrow metal cap. With this novel
design, the light absorption in graphene is enhanced while the metal absorption
loss is reduced simultaneously, which helps greatly improve the responsivity as
well as shorten the absorption region for achieving fast responses.
Furthermore, metal-graphene-metal sandwiched electrodes are introduced to
reduce the metal-graphene contact resistance, which is also helpful for
improving the response speed. When the photodetector operates at 2 {\mu}m, the
measured 3dB-bandwidth is >20 GHz (which is limited by the experimental setup)
while the 3dB-bandwith calculated from the equivalent circuit with the
parameters extracted from the measured S11 is as high as ~100 GHz. To the best
of our knowledge, it is the first time to report the waveguide photodetector at
2 {\mu}m with a 3dB-bandwidth over 20 GHz. Besides, the present photodetectors
also work very well at 1.55 {\mu}m. The measured responsivity is about 0.4 A/W
under a bias voltage of -0.3 V for an optical power of 0.16 mW, while the
measured 3dB-bandwidth is over 40 GHz (limited by the test setup) and the 3
dB-bandwidth estimated from the equivalent circuit is also as high as ~100 GHz,
which is one of the best results reported for silicon-graphene photodetectors
at 1.55 {\mu}m. |
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DOI: | 10.48550/arxiv.1907.12498 |