Programmable definition of nanogap electronic devices using self-inhibited reagent depletion

Brian Lam, Wendi Zhou, Shana O. Kelley*, Edward H. Sargent

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

18 Scopus citations

Abstract

Electrodes exhibiting controlled nanoscale separations are required in devices for light detection, semiconductor electronics and medical diagnostics. Here we use low-cost lithography to define micron-separated electrodes, which we downscale to create three-dimensional electrodes separated by nanoscale gaps. Only by devising a new strategy, which we term electrochemical self-inhibited reagent depletion, were we able to produce a robust self-limiting nanogap manufacturing technology. We investigate the method using experiment and simulation and find that, when electrodeposition is carried out using micron-spaced electrodes simultaneously poised at the same potential, these exhibit self-inhibited reagent depletion, leading to defined and robust nanogaps. Particularly remarkable is the formation of fractal electrodes that exhibit interpenetrating jagged elements that consistently avoid electrical contact. We showcase the new technology by fabricating photodetectors with responsivities (A/W) that are one hundred times higher than previously reported photodetectors operating at the same low (1-3 V) voltages. The new strategy adds to the nanofabrication toolkit method that unites top-down template definition with bottom-up three-dimensional nanoscale features.

Original languageEnglish (US)
Article number6940
JournalNature communications
Volume6
DOIs
StatePublished - Apr 27 2015

Funding

This research was sponsored by the Natural Sciences and Engineering Research Council (Discovery Grants to S.O.K. and E.H.S.) and the Ontario Research Fund. We thank Brandon Sutherland and Valerio Adinolfi for advice regarding SIRD photoconductor devices.

ASJC Scopus subject areas

  • General Chemistry
  • General Biochemistry, Genetics and Molecular Biology
  • General Physics and Astronomy

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