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Optimizing GaAs nanowire-based visible-light photodetectors

Li, X; Yu, X; Zeng, H; Boras, G; Shen, K; Zhang, Y; Wu, J; ... Liu, H; + view all (2021) Optimizing GaAs nanowire-based visible-light photodetectors. Applied Physics Letters , 119 (5) , Article 053105. 10.1063/5.0059438. Green open access

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Abstract

Sole surface passivation for III-V nanowire photodetectors exhibits limited photoresponse improvement. Consequently, a well-customized contact design is crucial. Here, GaAs nanowire-based metal-semiconductor-metal photodetectors via surface treatment and interfacial contact optimization are reported. The passivation strategy inhibits the surface recombination and, importantly, effectively reduces the Fermi-level pinning effect by the redistribution of surface states. It leads to the Schottky barrier height reduced from ∼0.63 to ∼0.36 eV at the Ni/GaAs nanowire contact. The design contributes to the prominently enhanced more than tenfold photoresponsivity and the much-shortened response time, in comparison with the pristine ones. When applying the design to the intrinsic GaAs nanowire photodetector, it demonstrates a responsivity of 4.5 × 104 A/W, a specific detectivity of 3.3 × 1014 Jones, and response time less than 50 ms under 520 nm laser illumination. Additionally, good repeatability of dynamic photo-switching characteristics and stability measured with slight degradation after 2 months are demonstrated. With the same approach, it is found that the responsivity could be further enhanced by over 50 times up to 6.4 × 105 A/W via fermi level adjustment in a p-doped single GaAs nanowire device. Featuring the nanoscale footprint and compact size, the results establish the GaAs nanowire as a promising and competitive candidate for high-performance and reliable nano-photodetection operating in the visible range.

Type: Article
Title: Optimizing GaAs nanowire-based visible-light photodetectors
Open access status: An open access version is available from UCL Discovery
DOI: 10.1063/5.0059438
Publisher version: https://doi.org/10.1063/5.0059438
Language: English
Additional information: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > MAPS Faculty Office
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > MAPS Faculty Office > Institute for Materials Discovery
URI: https://discovery.ucl.ac.uk/id/eprint/10133399
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