Edge-trimmed nanogaps in 2D materials for robust, scalable, and tunable lateral tunnel junctions

Hai Thai Nguyen, Yen Nguyen, Yen Hsun Su, Ya Ping Hsieh, Mario Hofmann

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Lateral tunnel junctions are fundamental building blocks for molecular electronics and novel sensors, but current fabrication approaches achieve device yields below 10%, which limits their appeal for circuit integration and large-scale application. We here demonstrate a new approach to reliably form nanometer-sized gaps between electrodes with high precision and unprecedented control. This advance in nanogap production is enabled by the unique properties of 2D materials-based contacts. The large difference in reactivity of 2D materials’ edges compared to their basal plane results in a sequential removal of atoms from the contact perimeter. The resulting trimming of exposed graphene edges in a remote hydrogen plasma proceeds at speeds of less than 1 nm per minute, permitting accurate control of the nanogap dimension through the etching process. Carrier transport measurements reveal the high quality of the nanogap, thus-produced tunnel junctions with a 97% yield rate, which represents a tenfold increase in productivity compared to previous reports. Moreover, 70% of tunnel junctions fall within a nanogap range of only 0.5 nm, representing an unprecedented uniformity in dimension. The presented edge-trimming approach enables the conformal narrowing of gaps and produces novel one-dimensional nano-trench geometries that can sustain larger tunneling currents than conventional 0D nano-junctions. Finally, the potential of our approach for future electronics was demonstrated by the realization of an atom-based memory.

Original languageEnglish
Article number981
Issue number4
Publication statusPublished - 2021 Apr

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Materials Science(all)


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