Infrared broadband enhancement of responsivity in Ge photodetectors decorated with Au nanoparticles
A broadband, high-performance infrared Ge photodetector decorated with Au nanoparticles (NPs) is proposed. Photoelectronic characterization demonstrated that the responsivity of devices decorated with Au NPs is as high as 3.95 A/W at a wavelength of 1550 nm. Compared with a Ge photodetector without...
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Veröffentlicht in: | Optics express 2021-04, Vol.29 (9), p.12941-12949 |
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Hauptverfasser: | , , , , , , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | A broadband, high-performance infrared Ge photodetector decorated with Au nanoparticles (NPs) is proposed. Photoelectronic characterization demonstrated that the responsivity of devices decorated with Au NPs is as high as 3.95 A/W at a wavelength of 1550 nm. Compared with a Ge photodetector without Au NPs, the responsivity of a device decorated with Au NPs is significantly increased, i.e., by more than 10 times in the entire range of infrared communication wavelengths, including the O, E, S, C, L, and U bands. The increase is ascribed to type-II energy-band alignment between Ge covered with Au NPs and bare Ge, instead of the localized surface-plasmon-resonance effect. The type-II energy-band alignment enhances the spatial electron-hole separation and restrains the electron-hole recombination, thus a larger photocurrent is observed. These results reflect the potential of this approach for achieving broadband, high-performance Ge photodetectors operating in the near-infrared communication band. |
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ISSN: | 1094-4087 1094-4087 |
DOI: | 10.1364/OE.423899 |