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
Hauptverfasser: Wang, Liming, Wang, Bo, Zhang, Yichi, Meng, Lingyao, Sun, Hao, Liu, Tao, Zhang, Ningning, Jiang, Zuimin, Hu, Huiyong
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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.
ISSN:1094-4087
1094-4087
DOI:10.1364/OE.423899