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In this work, evidence for acoustoelectric (AE) amplification in lateral-extensional thin-film piezoelectric-on- silicon (TPoS) resonant cavities for the first time is demonstrated. Due to the piezoelectric coupling, an evanescent electromagnetic wave is induced in the silicon (Si) layer that is a part of the resonant cavity, exchanging momentum with the carriers. Therefore, by injecting an electric current in this layer, the acoustic equivalent of Cherenkov radiation – AE amplification – can be realized. Such phenomenon is observed in a 1 GHz TPoS resonant cavity in which lateral field excitation is utilized to excite the acoustic wave.
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All-epitaxial resonant cavity enhanced long-wave infrared detectors for focal plane arrays
We demonstrate a monolithic all-epitaxial resonant-cavity architecture for long-wave infrared photodetectors with substrate-side illumination. An nBn detector with an ultra-thin (t≈350 nm) absorber layer is integrated into a leaky resonant cavity, formed using semi-transparent highly doped (n++) epitaxial layers, and aligned to the anti-node of the cavity's standing wave. The devices are characterized electrically and optically and demonstrate an external quantum efficiency of ∼25% at T=180 K in an architecture compatible with focal plane array configurations.
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- Award ID(s):
- 1926187
- PAR ID:
- 10440299
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- Applied Physics Letters
- Volume:
- 122
- Issue:
- 2
- ISSN:
- 0003-6951
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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